Fix `tree-sitter-mozjs` test failures introduced by #1141

[alexle0nte]

Following the grammar updates made by #1141, some tests are failing due to a parsing error in tree-sitter-javascript: tree-sitter/tree-sitter-javascript#351.
Below is a list of the failing tests, intended to track and fix them as the issue is resolved:

• pdf.js/extensions/firefox/tools/l10n.js
• pdf.js/src/display/optional_content_config.js
• pdf.js/docs/contents/js/bootstrap.min.js
• pdf.js/src/display/font_loader.js
• pdf.js/src/display/content_disposition.js
• pdf.js/src/display/pattern_helper.js
• pdf.js/src/display/canvas.js
• pdf.js/src/display/annotation_layer.js
• pdf.js/src/display/svg.js
• pdf.js/docs/contents/js/jquery-2.1.0.min.js
• pdf.js/src/display/display_utils.js
• pdf.js/src/display/editor/ink.js
• pdf.js/src/display/text_layer.js
• pdf.js/src/display/api.js
• pdf.js/src/core/fonts_utils.js
• pdf.js/src/core/primitives.js
• pdf.js/src/core/jpg.js
• pdf.js/src/core/jbig2_stream.js
• pdf.js/src/core/colorspace.js
• pdf.js/src/core/worker.js
• pdf.js/src/core/parser.js
• pdf.js/src/core/annotation.js
• pdf.js/src/core/evaluator.js
• pdf.js/src/core/function.js
• pdf.js/src/core/jpx_stream.js
• pdf.js/src/core/predictor_stream.js
• pdf.js/src/core/run_length_stream.js
• pdf.js/src/core/image.js
• pdf.js/src/core/writer.js
• pdf.js/src/core/operator_list.js
• pdf.js/src/core/jbig2.js
• pdf.js/src/core/jpx.js
• pdf.js/src/core/document.js
• pdf.js/src/core/name_number_tree.js
• pdf.js/src/core/cff_parser.js
• pdf.js/src/core/core_utils.js
• pdf.js/src/core/metadata_parser.js
• pdf.js/src/core/pattern.js
• pdf.js/src/core/fonts.js
• pdf.js/src/core/ccitt.js
• pdf.js/src/core/cff_font.js
• pdf.js/src/core/jpeg_stream.js
• pdf.js/src/core/struct_tree.js
• pdf.js/src/core/font_renderer.js
• pdf.js/src/core/glyf.js
• pdf.js/src/core/to_unicode_map.js
• pdf.js/src/core/cmap.js
• pdf.js/src/core/crypto.js
• pdf.js/src/core/type1_parser.js
• pdf.js/src/core/bidi.js
• pdf.js/src/core/chunked_stream.js
• pdf.js/src/core/type1_font.js
• pdf.js/src/core/opentype_file_builder.js
• pdf.js/src/core/catalog.js
• pdf.js/src/core/xref.js
• pdf.js/src/core/xml_parser.js
• pdf.js/src/core/flate_stream.js
• pdf.js/src/core/xfa/bind.js
• pdf.js/src/core/unicode.js
• pdf.js/src/core/xfa/text.js
• pdf.js/src/core/xfa/config.js
• pdf.js/src/core/xfa/som.js
• pdf.js/src/core/image_resizer.js
• pdf.js/src/core/xfa/xfa_object.js
• pdf.js/src/core/ascii_85_stream.js
• pdf.js/src/core/lzw_stream.js
• pdf.js/src/core/xfa/template.js
• pdf.js/src/scripting_api/field.js
• pdf.js/src/shared/fonts_utils.js
• pdf.js/src/scripting_api/aform.js
• pdf.js/src/shared/image_utils.js
• pdf.js/src/shared/murmurhash3.js
• pdf.js/src/shared/util.js
• pdf.js/test/stats/statcmp.js
• pdf.js/test/chromium/test-telemetry.js
• pdf.js/test/test.js
• pdf.js/test/integration/annotation_spec.js
• pdf.js/test/integration/freetext_editor_spec.js
• pdf.js/test/integration/ink_editor_spec.js
• pdf.js/test/resources/reftest-analyzer.js
• pdf.js/test/driver.js
• pdf.js/test/unit/crypto_spec.js
• pdf.js/test/integration/scripting_spec.js
• pdf.js/test/unit/ui_utils_spec.js
• pdf.js/test/unit/util_spec.js
• pdf.js/test/unit/struct_tree_spec.js
• pdf.js/test/unit/parser_spec.js
• pdf.js/test/unit/cff_parser_spec.js
• pdf.js/test/unit/annotation_spec.js
• pdf.js/test/unit/pdf_viewer_spec.js
• pdf.js/test/unit/pdf_find_controller_spec.js
• pdf.js/test/unit/scripting_spec.js
• pdf.js/examples/image_decoders/jpeg_viewer.js
• pdf.js/examples/node/pdf2svg.js
• pdf.js/examples/node/getinfo.js
• pdf.js/external/dist/webpack.js
• pdf.js/external/webL10n/l10n.js
• pdf.js/gulpfile.js
• pdf.js/test/unit/api_spec.js
• pdf.js/external/cmapscompress/optimize.js
• pdf.js/external/cmapscompress/compress.js
• pdf.js/web/firefox_print_service.js
• pdf.js/external/quickjs/quickjs-eval.js
• pdf.js/web/pdf_rendering_queue.js
• pdf.js/web/ui_utils.js
• pdf.js/web/event_utils.js
• pdf.js/web/debugger.js
• pdf.js/web/app.js
• pdf.js/web/pdf_page_view.js
• pdf.js/web/pdf_find_controller.js
• pdf.js/web/pdf_outline_viewer.js
• pdf.js/web/pdf_link_service.js
• pdf.js/web/pdf_thumbnail_viewer.js
• pdf.js/web/pdf_viewer.js
• pdf.js/web/text_highlighter.js
• pdf.js/web/view_history.js
• pdf.js/web/pdf_history.js
• pdf.js/web/pdf_sidebar.js