Everywhere: Rename to_{string => deprecated_string}() where applicable

This will make it easier to support both string types at the same time
while we convert code, and tracking down remaining uses.

One big exception is Value::to_string() in LibJS, where the name is
dictated by the ToString AO.

Userland/Libraries/LibJS/Runtime/Temporal/AbstractOperations.cpp

@@ -147,8 +147,8 @@ ThrowCompletionOr<Value> get_option(VM& vm, Object const& options, PropertyKey c
     if (!values.is_empty()) {
         // NOTE: Every location in the spec that invokes GetOption with type=boolean also has values=undefined.
         VERIFY(value.is_string());
-        if (!values.contains_slow(value.as_string().string()))
-            return vm.throw_completion<RangeError>(ErrorType::OptionIsNotValidValue, value.as_string().string(), property.as_string());
+        if (!values.contains_slow(value.as_string().deprecated_string()))
+            return vm.throw_completion<RangeError>(ErrorType::OptionIsNotValidValue, value.as_string().deprecated_string(), property.as_string());
     }
 
     // 9. Return value.
@@ -166,7 +166,7 @@ ThrowCompletionOr<DeprecatedString> to_temporal_overflow(VM& vm, Object const* o
     auto option = TRY(get_option(vm, *options, vm.names.overflow, OptionType::String, { "constrain"sv, "reject"sv }, "constrain"sv));
 
     VERIFY(option.is_string());
-    return option.as_string().string();
+    return option.as_string().deprecated_string();
 }
 
 // 13.5 ToTemporalDisambiguation ( options ), https://tc39.es/proposal-temporal/#sec-temporal-totemporaldisambiguation
@@ -180,7 +180,7 @@ ThrowCompletionOr<DeprecatedString> to_temporal_disambiguation(VM& vm, Object co
     auto option = TRY(get_option(vm, *options, vm.names.disambiguation, OptionType::String, { "compatible"sv, "earlier"sv, "later"sv, "reject"sv }, "compatible"sv));
 
     VERIFY(option.is_string());
-    return option.as_string().string();
+    return option.as_string().deprecated_string();
 }
 
 // 13.6 ToTemporalRoundingMode ( normalizedOptions, fallback ), https://tc39.es/proposal-temporal/#sec-temporal-totemporalroundingmode
@@ -203,7 +203,7 @@ ThrowCompletionOr<DeprecatedString> to_temporal_rounding_mode(VM& vm, Object con
         fallback.view()));
 
     VERIFY(option.is_string());
-    return option.as_string().string();
+    return option.as_string().deprecated_string();
 }
 
 // 13.7 NegateTemporalRoundingMode ( roundingMode ), https://tc39.es/proposal-temporal/#sec-temporal-negatetemporalroundingmode
@@ -240,7 +240,7 @@ ThrowCompletionOr<DeprecatedString> to_temporal_offset(VM& vm, Object const* opt
     auto option = TRY(get_option(vm, *options, vm.names.offset, OptionType::String, { "prefer"sv, "use"sv, "ignore"sv, "reject"sv }, fallback.view()));
 
     VERIFY(option.is_string());
-    return option.as_string().string();
+    return option.as_string().deprecated_string();
 }
 
 // 13.9 ToCalendarNameOption ( normalizedOptions ), https://tc39.es/proposal-temporal/#sec-temporal-tocalendarnameoption
@@ -250,7 +250,7 @@ ThrowCompletionOr<DeprecatedString> to_calendar_name_option(VM& vm, Object const
     auto option = TRY(get_option(vm, normalized_options, vm.names.calendarName, OptionType::String, { "auto"sv, "always"sv, "never"sv, "critical"sv }, "auto"sv));
 
     VERIFY(option.is_string());
-    return option.as_string().string();
+    return option.as_string().deprecated_string();
 }
 
 // 13.10 ToTimeZoneNameOption ( normalizedOptions ), https://tc39.es/proposal-temporal/#sec-temporal-totimezonenameoption
@@ -260,7 +260,7 @@ ThrowCompletionOr<DeprecatedString> to_time_zone_name_option(VM& vm, Object cons
     auto option = TRY(get_option(vm, normalized_options, vm.names.timeZoneName, OptionType::String, { "auto"sv, "never"sv, "critical"sv }, "auto"sv));
 
     VERIFY(option.is_string());
-    return option.as_string().string();
+    return option.as_string().deprecated_string();
 }
 
 // 13.11 ToShowOffsetOption ( normalizedOptions ), https://tc39.es/proposal-temporal/#sec-temporal-toshowoffsetoption
@@ -270,7 +270,7 @@ ThrowCompletionOr<DeprecatedString> to_show_offset_option(VM& vm, Object const&
     auto option = TRY(get_option(vm, normalized_options, vm.names.offset, OptionType::String, { "auto"sv, "never"sv }, "auto"sv));
 
     VERIFY(option.is_string());
-    return option.as_string().string();
+    return option.as_string().deprecated_string();
 }
 
 // 13.12 ToTemporalRoundingIncrement ( normalizedOptions, dividend, inclusive ), https://tc39.es/proposal-temporal/#sec-temporal-totemporalroundingincrement
@@ -531,7 +531,7 @@ ThrowCompletionOr<Optional<DeprecatedString>> get_temporal_unit(VM& vm, Object c
 
     Optional<DeprecatedString> value = option_value.is_undefined()
         ? Optional<DeprecatedString> {}
-        : option_value.as_string().string();
+        : option_value.as_string().deprecated_string();
 
     // 11. If value is listed in the Plural column of Table 13, then
     for (auto const& row : temporal_units) {

Userland/Libraries/LibJS/Runtime/Temporal/Calendar.cpp

@@ -126,7 +126,7 @@ ThrowCompletionOr<Vector<DeprecatedString>> calendar_fields(VM& vm, Object& cale
 
     Vector<DeprecatedString> result;
     for (auto& value : list)
-        result.append(value.as_string().string());
+        result.append(value.as_string().deprecated_string());
     return result;
 }
 
@@ -791,7 +791,7 @@ ThrowCompletionOr<double> resolve_iso_month(VM& vm, Object const& fields)
 
     // 6. Assert: Type(monthCode) is String.
     VERIFY(month_code.is_string());
-    auto& month_code_string = month_code.as_string().string();
+    auto& month_code_string = month_code.as_string().deprecated_string();
 
     // 7. If the length of monthCode is not 3, throw a RangeError exception.
     auto month_length = month_code_string.length();
@@ -953,7 +953,7 @@ ThrowCompletionOr<Object*> default_merge_calendar_fields(VM& vm, Object const& f
     // 3. For each element key of fieldsKeys, do
     for (auto& key : fields_keys) {
         // a. If key is not "month" or "monthCode", then
-        if (key.as_string().string() != vm.names.month.as_string() && key.as_string().string() != vm.names.monthCode.as_string()) {
+        if (key.as_string().deprecated_string() != vm.names.month.as_string() && key.as_string().deprecated_string() != vm.names.monthCode.as_string()) {
             auto property_key = MUST(PropertyKey::from_value(vm, key));
 
             // i. Let propValue be ? Get(fields, key).
@@ -987,7 +987,7 @@ ThrowCompletionOr<Object*> default_merge_calendar_fields(VM& vm, Object const& f
         }
 
         // See comment above.
-        additional_fields_keys_contains_month_or_month_code_property |= key.as_string().string() == vm.names.month.as_string() || key.as_string().string() == vm.names.monthCode.as_string();
+        additional_fields_keys_contains_month_or_month_code_property |= key.as_string().deprecated_string() == vm.names.month.as_string() || key.as_string().deprecated_string() == vm.names.monthCode.as_string();
     }
 
     // 6. If additionalFieldsKeys does not contain either "month" or "monthCode", then

Userland/Libraries/LibJS/Runtime/Temporal/CalendarPrototype.cpp

@@ -537,16 +537,16 @@ JS_DEFINE_NATIVE_FUNCTION(CalendarPrototype::fields)
         // iii. If fieldNames contains nextValue, then
         if (field_names.contains_slow(next_value)) {
             // 1. Let completion be ThrowCompletion(a newly created RangeError object).
-            auto completion = vm.throw_completion<RangeError>(ErrorType::TemporalDuplicateCalendarField, next_value.as_string().string());
+            auto completion = vm.throw_completion<RangeError>(ErrorType::TemporalDuplicateCalendarField, next_value.as_string().deprecated_string());
 
             // 2. Return ? IteratorClose(iteratorRecord, completion).
             return TRY(iterator_close(vm, iterator_record, move(completion)));
         }
 
         // iv. If nextValue is not one of "year", "month", "monthCode", "day", "hour", "minute", "second", "millisecond", "microsecond", "nanosecond", then
-        if (!next_value.as_string().string().is_one_of("year"sv, "month"sv, "monthCode"sv, "day"sv, "hour"sv, "minute"sv, "second"sv, "millisecond"sv, "microsecond"sv, "nanosecond"sv)) {
+        if (!next_value.as_string().deprecated_string().is_one_of("year"sv, "month"sv, "monthCode"sv, "day"sv, "hour"sv, "minute"sv, "second"sv, "millisecond"sv, "microsecond"sv, "nanosecond"sv)) {
             // 1. Let completion be ThrowCompletion(a newly created RangeError object).
-            auto completion = vm.throw_completion<RangeError>(ErrorType::TemporalInvalidCalendarFieldName, next_value.as_string().string());
+            auto completion = vm.throw_completion<RangeError>(ErrorType::TemporalInvalidCalendarFieldName, next_value.as_string().deprecated_string());
 
             // 2. Return ? IteratorClose(iteratorRecord, completion).
             return TRY(iterator_close(vm, iterator_record, move(completion)));

Userland/Libraries/LibJS/Runtime/Temporal/Duration.cpp

@@ -1789,7 +1789,7 @@ DeprecatedString temporal_duration_to_string(double years, double months, double
     }
 
     // 20. Return result.
-    return result.to_string();
+    return result.to_deprecated_string();
 }
 
 // 7.5.28 AddDurationToOrSubtractDurationFromDuration ( operation, duration, other, options ), https://tc39.es/proposal-temporal/#sec-temporal-adddurationtoorsubtractdurationfromduration

Userland/Libraries/LibJS/Runtime/Temporal/TimeZone.cpp

@@ -259,7 +259,7 @@ DeprecatedString format_time_zone_offset_string(double offset_nanoseconds)
     //    a. Let post be the empty String.
 
     // 14. Return the string-concatenation of sign, h, the code unit 0x003A (COLON), m, and post.
-    return builder.to_string();
+    return builder.to_deprecated_string();
 }
 
 // 11.6.6 FormatISOTimeZoneOffsetString ( offsetNanoseconds ), https://tc39.es/proposal-temporal/#sec-temporal-formatisotimezoneoffsetstring

Userland/Libraries/LibJS/Runtime/Temporal/ZonedDateTimePrototype.cpp

@@ -777,7 +777,7 @@ JS_DEFINE_NATIVE_FUNCTION(ZonedDateTimePrototype::with)
 
     // 18. Assert: Type(offsetString) is String.
     VERIFY(offset_string_value.is_string());
-    auto const& offset_string = offset_string_value.as_string().string();
+    auto const& offset_string = offset_string_value.as_string().deprecated_string();
 
     // 19. Let dateTimeResult be ? InterpretTemporalDateTimeFields(calendar, fields, options).
     auto date_time_result = TRY(interpret_temporal_date_time_fields(vm, calendar, *fields, *options));