[llvm] [WebAssembly] Fix lowering of (extending) loads from addrspace(1) globals (PR #155937)

[Sam Parker via llvm-commits]

sparker-arm wrote:

AFAIK, the main goal/appeal of global isel is reducing compilation time, hence the use by the GPU backends. I _think_ it's being used for AArch64 to replace fast-isel during debug, something like that. I'm not sure what the general status is performance wise. But yes, it should be an easier, but not small, undertaking for WebAssembly.

> I'm not sure that's feasible.

Try it. Give the parameter(s) a default value and hopefully you shouldn't have to touch too much stuff, almost certainly less than copying whole functions anyway :)

https://github.com/llvm/llvm-project/pull/155937