Re-use allocator in parser + lexer benchmarks.
I believe this is the recommended usage when parsing a bunch of files -
to re-use one allocator rather than create a fresh one for each run, so
it makes sense to me that this is what the benchmark should measure.
Doesn't show much difference on CodSpeed because it only runs the
benchmark once, and it treats allocations as free anyway. But I imagine
the difference may show up a bit more in a standard criterion benchmark.
Introduce invariant that only a single `lexer::Source` can exist on a thread at one time.
This is a preparatory step for #2341.
2 notes:
Restriction is only 1 x `ParserImpl` / `Lexer` / `Source` on 1 *thread* at a time, not globally. So this does not prevent parsing multiple files simultaneously on different threads.
Restriction does not apply to public type `Parser`, only `ParserImpl`. `ParserImpl`s are not created in created in `Parser::new`, but instead in `Parser::parse`, where they're created and then immediately consumed. So the end user is also free to create multiple `Parser` instances (if they want to for some reason) on the same thread.
This PR adds benchmarks for the lexer. I'm doing some work on optimizing
the lexer and I thought it'd be useful to see the effects of changes in
isolation, separate from the parser.
These benchmarks may not be ideal to keep long-term, but for now it'd be
useful.
In order to do so, it's necessary for `oxc_parser` crate to expose the
lexer, but have done that without adding it to the docs, and using an
alias `__lexer`.
