[llvm] [mlir] Fix LLVM_ENABLE_ABI_BREAKING_CHECKS macro check: use #if instead of #ifdef (PR #110185)

[David Blaikie via llvm-commits]

https://github.com/dwblaikie approved this pull request.

SGTM - this'll be an ABI break, of course - but we don't have an ABI stability between releases, so I don't think this would adversely affect anyone. We just have to be consistent within a release or version, and we were consistent (though inefficient) before this patch and we'll be consistent (though more efficient/lower memory usage, etc) afterwards.


https://github.com/llvm/llvm-project/pull/110185