SuccessChanges

Summary

  1. [Basic] Fix Wreturn-type gcc warning (NFC) (details)
  2. [Test] Add one more test with corner cases for non-wrapping IVs (details)
  3. [Sema] Fix MSVC "attribute is not recognized" warning (NFC) (details)
Commit d5e0868e5e321e2a2f3bf73599ae9239c5aaa0c9 by nullptr.cpp
[Basic] Fix Wreturn-type gcc warning (NFC)
The file was modifiedclang/include/clang/Basic/Diagnostic.h (diff)
Commit cb2bc9aad5de91cc5851aa707c39a68cfae65f0f by mkazantsev
[Test] Add one more test with corner cases for non-wrapping IVs
The file was addedllvm/test/CodeGen/X86/overflowing-iv.ll
Commit e9475a276267f1bc74d9624fc797c7a754b5b90b by nullptr.cpp
[Sema] Fix MSVC "attribute is not recognized" warning (NFC)

MSVC warning:
```
\llvm-project\clang\lib\Sema\SemaChecking.cpp(10323): warning C5030: attribute 'clang::fallthrough' is not recognized
```
The file was modifiedclang/lib/Sema/SemaChecking.cpp (diff)