[clang] [clang] Fix crashes when initializing constexpr int* with floating-point (PR #180376)

[Yanzuo Liu via cfe-commits]

zwuis wrote:

Thank you for your patch!

Please add a release note entry to "clang/docs/ReleaseNotes.rst".

Please add tests to "clang/test/". https://clang.llvm.org/docs/InternalsManual.html#testing might be useful.

"pointer initializer is not null" seemed misleading. IMO we should only emit the message saying "incompatible".

https://github.com/llvm/llvm-project/pull/180376