[clang] [Clang] Remove unnecessary return block after musttail call (PR #191198)

[Paweł Bylica via cfe-commits]

chfast wrote:

This change broke `ItaniumCXXABI::getOrCreateVirtualFunctionPointerThunk` (now fixed). I will give it some fuzzing time.

https://github.com/llvm/llvm-project/pull/191198