[Wasm RyuJIT] Contain Load Offsets When Possible

[adamperlin]

Our current codegen pattern for loads from a base offset could be compressed down.
For example, to load R2R data we do a pattern like:

global.get $imageBase
i32.const <rva>
i32.add
i32.load align=N offset=0

Ideally, we could contain the rva const as an offset in the load and drop the add to eliminate two instructions. So we'd have:

global.get $imageBase
i32.load align=N offset=<rva> 

Related #127654

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[AndyAyersMS]

We have this problem for shadow stack accesses too, lots of local.get 0; const; add, load (offs 0) sequences

[AndyAyersMS]

We have this problem for shadow stack accesses too, lots of local.get 0; const; add, load (offs 0) sequences

Actually it mainly seems to be for stores, for loads we do ok. For stores we have to materialize the address first.

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[adamperlin]

I believe this can be closed as of #131353