[clang] [flang] [flang][driver] Honour the toolchain default DWARF version (PR #217610)

[via cfe-commits]

github-actions[bot] wrote:

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

* 95790 tests passed
* 1955 tests skipped
* 1 test failed

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

### Clang
<details>
<summary>Clang.Modules/GH204633.cppm</summary>

```
Exit Code: 1

Command Output (stdout):
--
# RUN: at line 1
rm -rf /home/gha/actions-runner/_work/llvm-project/llvm-project/build/tools/clang/test/Modules/Output/GH204633.cppm.tmp
# executed command: rm -rf /home/gha/actions-runner/_work/llvm-project/llvm-project/build/tools/clang/test/Modules/Output/GH204633.cppm.tmp
# note: command had no output on stdout or stderr
# RUN: at line 2
split-file /home/gha/actions-runner/_work/llvm-project/llvm-project/clang/test/Modules/GH204633.cppm /home/gha/actions-runner/_work/llvm-project/llvm-project/build/tools/clang/test/Modules/Output/GH204633.cppm.tmp
# executed command: split-file /home/gha/actions-runner/_work/llvm-project/llvm-project/clang/test/Modules/GH204633.cppm /home/gha/actions-runner/_work/llvm-project/llvm-project/build/tools/clang/test/Modules/Output/GH204633.cppm.tmp
# note: command had no output on stdout or stderr
# RUN: at line 3
/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/24/include -nostdsysteminc -std=c++26 -triple x86_64-pc-win32 -fsyntax-only -fmodules    -fimplicit-module-maps -fmodules-cache-path=/home/gha/actions-runner/_work/llvm-project/llvm-project/build/tools/clang/test/Modules/Output/GH204633.cppm.tmp    -fmodule-map-file=/home/gha/actions-runner/_work/llvm-project/llvm-project/build/tools/clang/test/Modules/Output/GH204633.cppm.tmp/original.cppm -verify /home/gha/actions-runner/_work/llvm-project/llvm-project/build/tools/clang/test/Modules/Output/GH204633.cppm.tmp/original.cppm
# 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/24/include -nostdsysteminc -std=c++26 -triple x86_64-pc-win32 -fsyntax-only -fmodules -fimplicit-module-maps -fmodules-cache-path=/home/gha/actions-runner/_work/llvm-project/llvm-project/build/tools/clang/test/Modules/Output/GH204633.cppm.tmp -fmodule-map-file=/home/gha/actions-runner/_work/llvm-project/llvm-project/build/tools/clang/test/Modules/Output/GH204633.cppm.tmp/original.cppm -verify /home/gha/actions-runner/_work/llvm-project/llvm-project/build/tools/clang/test/Modules/Output/GH204633.cppm.tmp/original.cppm
# .---command stderr------------
# | error: 'expected-error' diagnostics expected but not seen: 
# |   File /home/gha/actions-runner/_work/llvm-project/llvm-project/build/tools/clang/test/Modules/Output/GH204633.cppm.tmp/original.cppm Line 4 (directive at /home/gha/actions-runner/_work/llvm-project/llvm-project/build/tools/clang/test/Modules/Output/GH204633.cppm.tmp/original.cppm:1): unexpected preprocessing token '{' after module name
# | error: 'expected-error' diagnostics seen but not expected: 
# |   File /home/gha/actions-runner/_work/llvm-project/llvm-project/build/tools/clang/test/Modules/Output/GH204633.cppm.tmp/original.cppm Line 4: unexpected '{' after module name, only ';' and '[' (start of attribute specifier sequence) are allowed
# | 2 errors generated.
# `-----------------------------
# error: command failed with exit status: 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/217610