LibJS: Allow string as parameter in Temporal's round() / total()

This is a normative change in the Temporal spec.

See: 1f0c586

Userland/Libraries/LibJS/Tests/builtins/Temporal/Instant/Instant.prototype.round.js

@@ -21,6 +21,13 @@ describe("correct behavior", () => {
             }).epochNanoseconds
         ).toBe(1800000000000n);
     });
+
+    test("string argument is implicitly converted to options object", () => {
+        const instant = new Temporal.Instant(1111111111111n);
+        expect(
+            instant.round("second").equals(instant.round({ smallestUnit: "second" }))
+        ).toBeTrue();
+    });
 });
 
 describe("errors", () => {

Userland/Libraries/LibJS/Tests/builtins/Temporal/PlainDateTime/PlainDateTime.prototype.round.js

@@ -81,6 +81,13 @@ describe("correct behavior", () => {
         expect(fifthRoundedPlainDateTime.microsecond).toBe(0);
         expect(fifthRoundedPlainDateTime.nanosecond).toBe(0);
     });
+
+    test("string argument is implicitly converted to options object", () => {
+        const plainDateTime = new Temporal.PlainDateTime(2021, 11, 3, 18, 8, 10, 100, 200, 300);
+        expect(
+            plainDateTime.round("minute").equals(plainDateTime.round({ smallestUnit: "minute" }))
+        ).toBeTrue();
+    });
 });
 
 describe("errors", () => {

Userland/Libraries/LibJS/Tests/builtins/Temporal/PlainTime/PlainTime.prototype.round.js

@@ -61,6 +61,13 @@ describe("correct behavior", () => {
         expect(fifthRoundedPlainTime.microsecond).toBe(0);
         expect(fifthRoundedPlainTime.nanosecond).toBe(0);
     });
+
+    test("string argument is implicitly converted to options object", () => {
+        const plainTime = new Temporal.PlainTime(18, 15, 9, 100, 200, 300);
+        expect(
+            plainTime.round("minute").equals(plainTime.round({ smallestUnit: "minute" }))
+        ).toBeTrue();
+    });
 });
 
 describe("errors", () => {

Userland/Libraries/LibJS/Tests/builtins/Temporal/ZonedDateTime/ZonedDateTime.prototype.round.js

@@ -29,6 +29,16 @@ describe("correct behavior", () => {
             }).epochNanoseconds
         ).toBe(1800000000000n);
     });
+
+    test("string argument is implicitly converted to options object", () => {
+        const zonedDateTime = new Temporal.ZonedDateTime(
+            1111111111111n,
+            new Temporal.TimeZone("UTC")
+        );
+        expect(
+            zonedDateTime.round("second").equals(zonedDateTime.round({ smallestUnit: "second" }))
+        ).toBeTrue();
+    });
 });
 
 describe("errors", () => {