[llvm] [mlir] Revert "Fix LLVM_ENABLE_ABI_BREAKING_CHECKS macro check: use #if inst… (PR #110923)

[Benoit Jacob via llvm-commits]

bjacob wrote:

> I see #110918 supposedly fixes these issues, but we can reland the original PR along with those fixes

SG - so I'll let you fold my fixes in https://github.com/llvm/llvm-project/pull/110918 into the new PR.

https://github.com/llvm/llvm-project/pull/110923