[llvm] [llvm][dsymutil] Use the DW_AT_name of the uniqued DIE for insertion into .debug_names (PR #168513)

[via llvm-commits]

github-actions[bot] wrote:

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

* 166069 tests passed
* 2834 tests skipped
* 1 test failed

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

### LLVM
<details>
<summary>LLVM.tools/dsymutil/null-die.test</summary>

```
Exit Code: -6

Command Output (stdout):
--
# RUN: at line 1
/home/gha/actions-runner/_work/llvm-project/llvm-project/build/bin/dsymutil -f -oso-prepend-path=/home/gha/actions-runner/_work/llvm-project/llvm-project/llvm/test/tools/dsymutil/Inputs/ -y /home/gha/actions-runner/_work/llvm-project/llvm-project/llvm/test/tools/dsymutil/null-die.test -no-output 2>&1    |  /home/gha/actions-runner/_work/llvm-project/llvm-project/build/bin/FileCheck /home/gha/actions-runner/_work/llvm-project/llvm-project/llvm/test/tools/dsymutil/null-die.test
# executed command: /home/gha/actions-runner/_work/llvm-project/llvm-project/build/bin/dsymutil -f -oso-prepend-path=/home/gha/actions-runner/_work/llvm-project/llvm-project/llvm/test/tools/dsymutil/Inputs/ -y /home/gha/actions-runner/_work/llvm-project/llvm-project/llvm/test/tools/dsymutil/null-die.test -no-output
# note: command had no output on stdout or stderr
# error: command failed with exit status: -6
# executed command: /home/gha/actions-runner/_work/llvm-project/llvm-project/build/bin/FileCheck /home/gha/actions-runner/_work/llvm-project/llvm-project/llvm/test/tools/dsymutil/null-die.test
# note: command had no output on stdout or stderr

--

```
</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/168513