perf(syntax): optimize `is_identifier_name` (#5425) #16083

Job	Run time
Benchmark (lexer)	1m 19s
Build Linter Benchmark	5m 7s
Benchmark (parser)	1m 39s
Benchmark (transformer)	6m 10s
Benchmark (isolated_declarations)	1m 42s
Benchmark (semantic)	1m 47s
Benchmark (minifier)	2m 17s
Benchmark (codegen)	1m 30s
Benchmark (sourcemap)	1m 47s
Benchmark linter (0)	1m 59s
Benchmark linter (1)	1m 20s
Upload benchmarks	15s
	26m 52s

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