compiler: implement pos-only mode for implicit spaces

[pdubroy]

Implement a "pos-only" mode for implicit space skipping. In pos-only mode, we don't build a CST, do failure recording, etc. This results in a significant performance improvement, and a huge memory savings.

Before

$ bin/es5bench-wasm
Compile: 66ms
......
JS match: 3312.9ms ± 284.9ms (n=3)
Wasm match: 79.1ms ± 26.7ms (n=3)
Wasm vs JS match: 41.9x
Wasm memory: 174.0MB

After

$ bin/es5bench-wasm
Compile: 57ms
......
JS match: 3311.9ms ± 113.2ms (n=3)
Wasm match: 55.8ms ± 15.7ms (n=3)
Wasm vs JS match: 59.3x
Wasm memory: 87.0MB

[pkg-pr-new]

Open in StackBlitz

npm i https://pkg.pr.new/ohmjs/ohm/@ohm-js/compiler@602

npm i https://pkg.pr.new/ohmjs/ohm/ohm-js@602

npm i https://pkg.pr.new/ohmjs/ohm/@ohm-js/to-ast-compat@602

commit: 34ee81e