[clang] [Clang] Deleting an incomplete enum type is not an error (PR #118455)

[Mike Hommey via cfe-commits]

glandium wrote:

cvise has reduced my testcase to 
```
union StyleColorFunctionStyleColorFunction *mRaw {
  delete mRaw
```
... which is nowhere close to the real thing and nowhere close to legal C++ at all.

Well, that definitely shouldn't trigger a crash, though.

https://github.com/llvm/llvm-project/pull/118455