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

[Sam Parker via llvm-commits]

sparker-arm wrote:

> Last we left off, you were experimenting with https://github.com/llvm/llvm-project/pull/157627

Yeah, I'm not going to have the time to continue with that rabbit hole.

> In that case, I should rebase, make sure it still works, and request a final review?

I'd say yes, and don't duplicate the existing combine logic into the wasm backend. Did we agree that tablegen patterns could probably 'fix' the missed combines?

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