[clang] [llvm] [clang][Hexagon] Add Picolibc as part of triple (PR #169613)

[via llvm-commits]

github-actions[bot] wrote:

<!--PREMERGE ADVISOR COMMENT: Windows-->
# :window: Windows x64 Test Results

* 77014 tests passed
* 1947 tests skipped

All tests passed but another part of the build **failed**. Click on a failure below to see the details.

<details>
<summary>[code=1] tools/clang/lib/Driver/CMakeFiles/obj.clangDriver.dir/ToolChains/Hexagon.cpp.obj</summary>

```
FAILED: [code=1] tools/clang/lib/Driver/CMakeFiles/obj.clangDriver.dir/ToolChains/Hexagon.cpp.obj
sccache C:\clang\clang-msvc\bin\clang-cl.exe  /nologo -TP -DCLANG_BUILD_STATIC -DGTEST_HAS_RTTI=0 -DUNICODE -D_CRT_NONSTDC_NO_DEPRECATE -D_CRT_NONSTDC_NO_WARNINGS -D_CRT_SECURE_NO_DEPRECATE -D_CRT_SECURE_NO_WARNINGS -D_GLIBCXX_ASSERTIONS -D_HAS_EXCEPTIONS=0 -D_SCL_SECURE_NO_DEPRECATE -D_SCL_SECURE_NO_WARNINGS -D_UNICODE -D__STDC_CONSTANT_MACROS -D__STDC_FORMAT_MACROS -D__STDC_LIMIT_MACROS -Itools\clang\lib\Driver -IC:\_work\llvm-project\llvm-project\clang\lib\Driver -IC:\_work\llvm-project\llvm-project\clang\include -Itools\clang\include -Iinclude -IC:\_work\llvm-project\llvm-project\llvm\include /DWIN32 /D_WINDOWS   /Zc:inline /Zc:__cplusplus /Oi /Brepro /bigobj /permissive- -Werror=unguarded-availability-new /W4  -Wextra -Wno-unused-parameter -Wwrite-strings -Wcast-qual -Wmissing-field-initializers -Wimplicit-fallthrough -Wcovered-switch-default -Wno-noexcept-type -Wnon-virtual-dtor -Wdelete-non-virtual-dtor -Wsuggest-override -Wstring-conversion -Wno-pass-failed -Wmisleading-indentation -Wctad-maybe-unsupported /Gw /O2 /Ob2  -MD  /EHs-c- /GR- -UNDEBUG -std:c++17 /showIncludes /Fotools\clang\lib\Driver\CMakeFiles\obj.clangDriver.dir\ToolChains\Hexagon.cpp.obj /Fdtools\clang\lib\Driver\CMakeFiles\obj.clangDriver.dir\ -c -- C:\_work\llvm-project\llvm-project\clang\lib\Driver\ToolChains\Hexagon.cpp
C:\_work\llvm-project\llvm-project\clang\lib\Driver\ToolChains\Hexagon.cpp(927,5): error: expected expression
927 |     llvm_unreachable();
|     ^
C:\_work\llvm-project\llvm-project\llvm\include\llvm/Support/ErrorHandling.h(165,40): note: expanded from macro 'llvm_unreachable'
165 |   ::llvm::llvm_unreachable_internal(msg, __FILE__, __LINE__)
|                                        ^
C:\_work\llvm-project\llvm-project\clang\lib\Driver\ToolChains\Hexagon.cpp(926,3): warning: default label in switch which covers all enumeration values [-Wcovered-switch-default]
926 |   default:
|   ^
1 warning and 1 error generated.
```
</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/169613