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

[via cfe-commits]

github-actions[bot] wrote:

<!--PREMERGE ADVISOR COMMENT: Linux-->
# :penguin: Linux x64 Test Results

* 87288 tests passed
* 1393 tests skipped
* 1 test failed

## Failed Tests
(click on a test name to see its output)

### Clang
<details>
<summary>Clang.CodeGenCXX/ptrauth-member-function-pointer.cpp</summary>

```
Exit Code: 2

Command Output (stdout):
--
# RUN: at line 1
/home/gha/actions-runner/_work/llvm-project/llvm-project/build/bin/clang -cc1 -internal-isystem /home/gha/actions-runner/_work/llvm-project/llvm-project/build/lib/clang/23/include -nostdsysteminc -triple arm64-apple-ios   -fptrauth-calls -fptrauth-intrinsics -emit-llvm -std=c++11 -O1 -disable-llvm-passes -o - /home/gha/actions-runner/_work/llvm-project/llvm-project/clang/test/CodeGenCXX/ptrauth-member-function-pointer.cpp | /home/gha/actions-runner/_work/llvm-project/llvm-project/build/bin/FileCheck -check-prefixes=CHECK,NODEBUG,DARWIN /home/gha/actions-runner/_work/llvm-project/llvm-project/clang/test/CodeGenCXX/ptrauth-member-function-pointer.cpp
# executed command: /home/gha/actions-runner/_work/llvm-project/llvm-project/build/bin/clang -cc1 -internal-isystem /home/gha/actions-runner/_work/llvm-project/llvm-project/build/lib/clang/23/include -nostdsysteminc -triple arm64-apple-ios -fptrauth-calls -fptrauth-intrinsics -emit-llvm -std=c++11 -O1 -disable-llvm-passes -o - /home/gha/actions-runner/_work/llvm-project/llvm-project/clang/test/CodeGenCXX/ptrauth-member-function-pointer.cpp
# .---command stderr------------
# | Instruction referencing instruction not embedded in a basic block!
# |   %call = musttail call [2 x i64] %4(ptr noundef nonnull align 8 dereferenceable(8) %0) [ "ptrauth"(i32 0, i64 %6) ]
# |   ret [2 x i64] %call
# | fatal error: error in backend: Broken module found, compilation aborted!
# `-----------------------------
# error: command failed with exit status: 70
# executed command: /home/gha/actions-runner/_work/llvm-project/llvm-project/build/bin/FileCheck -check-prefixes=CHECK,NODEBUG,DARWIN /home/gha/actions-runner/_work/llvm-project/llvm-project/clang/test/CodeGenCXX/ptrauth-member-function-pointer.cpp
# .---command stderr------------
# | FileCheck error: '<stdin>' is empty.
# | FileCheck command line:  /home/gha/actions-runner/_work/llvm-project/llvm-project/build/bin/FileCheck -check-prefixes=CHECK,NODEBUG,DARWIN /home/gha/actions-runner/_work/llvm-project/llvm-project/clang/test/CodeGenCXX/ptrauth-member-function-pointer.cpp
# `-----------------------------
# error: command failed with exit status: 2

--

```
</details>

If these failures are unrelated to your changes (for example tests are broken or flaky at HEAD), please open an issue at https://github.com/llvm/llvm-project/issues and add the `infrastructure` label.

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