[llvm] wasm: recognize `any_true` and `all_true` (PR #155885)

[Sam Parker via llvm-commits]

sparker-arm wrote:

But if we change this code, how is the behavior going to be controlled? I wonder how often the default code path is actually executed... I kinda assume most backends only have 'legal' reductions for those they can map directly or the IR gets expanded. 

https://github.com/llvm/llvm-project/pull/155885