[llvm] [GlobalISel] Rewrite binop_left_to_zero using MIR Patterns (PR #177924)

[Luisa Cicolini via llvm-commits]

luisacicolini wrote:

LGTM, thank you! Let's wait for the approval from a backend expert (e.g. @qcolombet)

https://github.com/llvm/llvm-project/pull/177924