WASM compilation issues

[jkbz64]

Currently tree-sitter build -w process gets OOM killed due to clang issues that get triggered by the current grammar implementaton.

Will continue optimizing grammar's ACTION_COUNT and STATE_COUNT but it will probably require a fix in clang as even compilation with much reduced subset of statements hogs too much ram and takes too long.

[jkbz64]

LLVM fix landed, now we need to wait for a release and a bump in wasi-sdk/emscripten.