Also optimize the memory allocation in string escape. The default size in `serde_json` is 1024 for String type, we pre allocate `string.len() * 2 + 2` for every string to reduce re-allocate in escaping.
I've tried to hand write SIMD implementation, but it's too complex, so I uses the `v_jsonescape` here. But it doesn't support `aarch64` and `wasm32` simd implementation, we need to contribute to it!
Reduce memory copies when encoding source map as JSON, extending approach taken in #4476 to also avoid memory copies for source texts.
I believe reason this shows no benefit on benchmarks is because our benchmarks only create a source map from a single source file, but it should result in a speed-up when there are multiple sources.
Because the `token_chunks` need to pre-visit tokens and collect, it
could be done at add tokens phase. So here export it let rolldown could
be improve `renderChunks` sourcemap encode.
The rolldown plugin hook could return an object map, cast it to string
at node, and decode it has unnecessary json overhead at rust. So here
export an new function to let rolldown could using `JSONSourceMap` to
generate `Sourcemap`.
The sourcemap implement port from
[rust-sourcemap](https://github.com/getsentry/rust-sourcemap), but has
some different with it.
- Encode sourcemap at parallel, including quote `sourceContent` and
encode token to `vlq` mappings.
- Avoid `Sourcemap` some methods overhead, like `SourceMap::tokens()`
caused extra overhead at common cases. Here using `SourceViewToken` to
instead of it.
