Auto merge of #154223 - malezjaa:refactor-typecheck-op, r=adwinwhite

refactor rustc_hir_typeck/src/op.rs





Fixes rust-lang/rust#64297

This is a refactoring PR with no logic or behaviour changes. I tried to improve readability of op.rs, which had a few very large functions using some suboptimal syntax. I broke these up into smaller helpers.