[clang] [clang][Modules] Keep existing global definition on type mismatch in GetOrCreateLLVMGlobal (PR #223877)

[Chuanqi Xu via cfe-commits]

https://github.com/ChuanqiXu9 commented:

This looks like a workaround to the real issue. Why can't the global be merged properly?

https://github.com/llvm/llvm-project/pull/223877