[llvm] [GISel][TableGen] Fix accidental operand name clashes in patterns (PR #74492)

[Anatoly Trosinenko via llvm-commits]

atrosinenko wrote:

A few fixes after rebase:
* a recent commit of @Pierre-vh added `// Size: ...` comments - just updated these two comments in the `GlobalISelEmitter.td` test file to contain the new values
* fixed wording in the comment: "matcher" -> "predicate"

https://github.com/llvm/llvm-project/pull/74492