[Mlir-commits] [mlir] [MLIR][CMake] Fix LLVM_DEFINITIONS handling in standalone example (PR #234653)

[Maksim Levental]

makslevental wrote:

> For downstream out-of-tree users, this is not guarunteed to yield the same answer as the LLVM_DEFINITIONS set through LLVMConfig.cmake when consuming a built distributions.

I've never seen `LLVM_DEFINITIONS` used this way (manual `add_definitions`). Not that I don't believe it's out there. Would it be possible to just unify on only HandleLLVMOptions setting and adding the compile flags? Ie making manual `add_definitions(${LLVM_DEFINITIONS_LIST})` a "user error"? 

https://github.com/llvm/llvm-project/pull/234653