fix(parser): produce syntax error for export enum and similar ts syntaxes

[Boshen]

fixes #13205
closes #13206

[graphite-app]

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[Copilot]

Pull Request Overview

This PR fixes the parser to properly handle TypeScript-specific syntax like export enum, export interface, and similar constructs by adding TypeScript context checks and reorganizing the declaration parsing logic.

• Moves variable declaration parsing to handle var, let, and const first
• Adds self.is_ts checks to TypeScript-specific declaration types to prevent parsing them in JavaScript contexts
• Removes the unused is_variable_declaration() helper method

Reviewed Changes

Copilot reviewed 2 out of 4 changed files in this pull request and generated 1 comment.

File	Description
crates/oxc_parser/src/ts/statement.rs	Reorganizes declaration parsing logic and adds TypeScript context checks
crates/oxc_parser/src/lexer/kind.rs	Removes unused is_variable_declaration() helper method

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[codspeed-hq]

CodSpeed Instrumentation Performance Report

Merging #13208 will not alter performance

_{Comparing 08-19-fix_parser_produce_syntax_error_for_export_enum_and_similar_ts_syntaxes (7970f8e) with main (51ca0ad)¹}

Summary

✅ 34 untouched benchmarks

Footnotes

1. No successful run was found on main (63abd7c) during the generation of this report, so 51ca0ad was used instead as the comparison base. There might be some changes unrelated to this pull request in this report. ↩