[clang] [AMDGPU] Add builtins for wave reduction intrinsics (PR #161816)

[via cfe-commits]

github-actions[bot] wrote:

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

* 91129 tests passed
* 2411 tests skipped
* 1 test failed

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

### RealtimeSanitizer-Unit
<details>
<summary>RealtimeSanitizer-Unit._/Rtsan-x86_64-Test/RtsanFileTest/OpenCreatesFileWithProperMode</summary>

```
Script:
--
/home/gha/actions-runner/_work/llvm-project/llvm-project/build/runtimes/runtimes-bins/compiler-rt/lib/rtsan/tests/./Rtsan-x86_64-Test --gtest_filter=RtsanFileTest.OpenCreatesFileWithProperMode
--
/home/gha/actions-runner/_work/llvm-project/llvm-project/compiler-rt/lib/rtsan/tests/rtsan_test_interceptors_posix.cpp:440
Value of: stat(GetTemporaryFilePath(), &st)
Expected: is equal to 0
  Actual: -1


```
</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/161816