[llvm] `__builtin.canonicalize` in common code (PR #142105)

[Jay Foad via llvm-commits]

jayfoad wrote:

> `__builtin.canonicalize` in common code

This patch is about the LLVM intrinsic, not the Clang builtin, so the title should say `llvm.canonicalize`

https://github.com/llvm/llvm-project/pull/142105