Everywhere: Replace single-char StringView op. arguments with chars

This prevents us from needing a sv suffix, and potentially reduces the
need to run generic code for a single character (as contains,
starts_with, ends_with etc. for a char will be just a length and
equality check).

No functional changes.

Userland/Shell/AST.cpp

@@ -2665,7 +2665,7 @@ RefPtr<Value> ReadRedirection::run(RefPtr<Shell> shell)
         return make_ref_counted<ListValue>({});
 
     StringBuilder builder;
-    builder.join(" ", path_segments);
+    builder.join(' ', path_segments);
 
     command.redirections.append(PathRedirection::create(builder.to_string(), m_fd, PathRedirection::Read));
     return make_ref_counted<CommandValue>(move(command));
@@ -2695,7 +2695,7 @@ RefPtr<Value> ReadWriteRedirection::run(RefPtr<Shell> shell)
         return make_ref_counted<ListValue>({});
 
     StringBuilder builder;
-    builder.join(" ", path_segments);
+    builder.join(' ', path_segments);
 
     command.redirections.append(PathRedirection::create(builder.to_string(), m_fd, PathRedirection::ReadWrite));
     return make_ref_counted<CommandValue>(move(command));
@@ -3052,7 +3052,7 @@ void Juxtaposition::highlight_in_editor(Line::Editor& editor, Shell& shell, High
 
         StringBuilder path_builder;
         path_builder.append(tilde_value);
-        path_builder.append("/");
+        path_builder.append('/');
         path_builder.append(bareword_value);
         auto path = path_builder.to_string();
 
@@ -3183,8 +3183,8 @@ RefPtr<Value> StringPartCompose::run(RefPtr<Shell> shell)
         return make_ref_counted<ListValue>({});
 
     StringBuilder builder;
-    builder.join(" ", left);
-    builder.join(" ", right);
+    builder.join(' ', left);
+    builder.join(' ', right);
 
     return make_ref_counted<StringValue>(builder.to_string());
 }
@@ -3347,7 +3347,7 @@ RefPtr<Value> WriteAppendRedirection::run(RefPtr<Shell> shell)
         return make_ref_counted<ListValue>({});
 
     StringBuilder builder;
-    builder.join(" ", path_segments);
+    builder.join(' ', path_segments);
 
     command.redirections.append(PathRedirection::create(builder.to_string(), m_fd, PathRedirection::WriteAppend));
     return make_ref_counted<CommandValue>(move(command));
@@ -3377,7 +3377,7 @@ RefPtr<Value> WriteRedirection::run(RefPtr<Shell> shell)
         return make_ref_counted<ListValue>({});
 
     StringBuilder builder;
-    builder.join(" ", path_segments);
+    builder.join(' ', path_segments);
 
     command.redirections.append(PathRedirection::create(builder.to_string(), m_fd, PathRedirection::Write));
     return make_ref_counted<CommandValue>(move(command));
@@ -3724,7 +3724,7 @@ String TildeValue::resolve_as_string(RefPtr<Shell> shell)
 Vector<String> TildeValue::resolve_as_list(RefPtr<Shell> shell)
 {
     StringBuilder builder;
-    builder.append("~");
+    builder.append('~');
     builder.append(m_username);
 
     if (!shell)

Userland/Shell/Builtin.cpp

@@ -207,11 +207,11 @@ int Shell::builtin_type(int argc, char const** argv)
             if (!dont_show_function_source) {
                 StringBuilder builder;
                 builder.append(fn.name);
-                builder.append("(");
+                builder.append('(');
                 for (size_t i = 0; i < fn.arguments.size(); i++) {
                     builder.append(fn.arguments[i]);
                     if (!(i == fn.arguments.size() - 1))
-                        builder.append(" ");
+                        builder.append(' ');
                 }
                 builder.append(") {\n"sv);
                 if (fn.body) {
@@ -448,7 +448,7 @@ int Shell::builtin_export(int argc, char const** argv)
             if (value) {
                 auto values = value->resolve_as_list(*this);
                 StringBuilder builder;
-                builder.join(" ", values);
+                builder.join(' ', values);
                 parts.append(builder.to_string());
             } else {
                 // Ignore the export.

Userland/Shell/Formatter.cpp

@@ -41,7 +41,7 @@ String Formatter::format()
 
     auto string = current_builder().string_view();
 
-    if (!string.ends_with(" "))
+    if (!string.ends_with(' '))
         current_builder().append(m_trivia);
 
     return current_builder().to_string();

Userland/Shell/Parser.cpp

@@ -1969,7 +1969,7 @@ RefPtr<AST::Node> Parser::parse_glob()
                 textbuilder.append(bareword->text());
             } else if (glob_after->is_tilde()) {
                 auto bareword = static_cast<AST::Tilde*>(glob_after.ptr());
-                textbuilder.append("~");
+                textbuilder.append('~');
                 textbuilder.append(bareword->text());
             } else {
                 return create<AST::SyntaxError>(String::formatted("Invalid node '{}' in glob position, escape shell special characters", glob_after->class_name()));

Userland/Shell/Shell.cpp

@@ -390,7 +390,7 @@ String Shell::local_variable_or(StringView name, String const& replacement) cons
     auto value = lookup_local_variable(name);
     if (value) {
         StringBuilder builder;
-        builder.join(" ", value->resolve_as_list(*this));
+        builder.join(' ', value->resolve_as_list(*this));
         return builder.to_string();
     }
     return replacement;
@@ -839,7 +839,7 @@ ErrorOr<RefPtr<Job>> Shell::run_command(const AST::Command& command)
     close(sync_pipe[1]);
 
     StringBuilder cmd;
-    cmd.join(" ", command.argv);
+    cmd.join(' ', command.argv);
 
     auto command_copy = AST::Command(command);
     // Clear the next chain if it's to be immediately executed

Userland/Shell/SyntaxHighlighter.cpp

@@ -128,7 +128,7 @@ private:
             span.attributes.color = m_palette.syntax_keyword();
             span.attributes.bold = true;
             m_is_first_in_command = false;
-        } else if (node->text().starts_with("-")) {
+        } else if (node->text().starts_with('-')) {
             span.attributes.color = m_palette.syntax_preprocessor_statement();
         } else {
             span.attributes.color = m_palette.base_text();