[clang] [llvm] [MTE] Add an attribute to opt-in memory tagging of global variables while using fsanitize=memtag-globals (#166380) (PR #182028)

[via cfe-commits]

github-actions[bot] wrote:

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

* 176823 tests passed
* 4475 tests skipped
* 1 test failed

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

### MemorySanitizer-Unit
<details>
<summary>MemorySanitizer-Unit._/Msan-x86_64-Test/MemorySanitizer/bind_getsockname</summary>

```
Script:
--
/home/gha/actions-runner/_work/llvm-project/llvm-project/build/runtimes/runtimes-bins/compiler-rt/lib/msan/tests/./Msan-x86_64-Test --gtest_filter=MemorySanitizer.bind_getsockname
--
/home/gha/actions-runner/_work/llvm-project/llvm-project/compiler-rt/lib/msan/tests/msan_test.cpp:881
Expected equality of these values:
  0
  res
    Which is: -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/182028