Optimize expandType for JS target

[MaxGraey]

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[dcodeIO]

With this becoming more common, wdyt of moving these optimizations into a helper? Perhaps something like

export function i32_load(ptr: usize): i32 {
  return ASC_TARGET
    ? binaryen.__i32_load(ptr)
    : binaryen.HEAP32[ptr >> 2];
}

and always use this one instead?

[MaxGraey]

I'm not sure. It may have some overhead on JS side

[dcodeIO]

Yeah, depends on how well the JIT handles it. Seems rather trivial, though, perhaps it does?

[MaxGraey]

Merging. We could return to more granular approach later