JSSpecCompiler: Parse "Perform <expression>." steps

Author: https://github.com/DanShaders
Commit: ddf26a768c
Pull-request: https://github.com/SerenityOS/serenity/pull/23123
Reviewed-by: https://github.com/ADKaster ✅

Meta/Lagom/Tools/CodeGenerators/JSSpecCompiler/Parser/TextParser.h

@@ -84,6 +84,7 @@ private:
     TextParseErrorOr<Tree> parse_return_statement();
     TextParseErrorOr<Tree> parse_assert();
     TextParseErrorOr<Tree> parse_assignment();
+    TextParseErrorOr<Tree> parse_perform();
     TextParseErrorOr<Tree> parse_simple_step_or_inline_if_branch();
     TextParseErrorOr<IfConditionParseResult> parse_if_beginning();
     TextParseErrorOr<Tree> parse_inline_if_else();