[clang] [clang-linker-wrapper][lit] Fix SPIR-V OpenMP ELF test (PR #126098)

[LLVM Continuous Integration via cfe-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `reverse-iteration` running on `hexagon-build-02` while building `clang` at step 6 "check_all".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/110/builds/3812

<details>
<summary>Here is the relevant piece of the build log for the reference</summary>

```
Step 6 (check_all) failure: test (failure)
******************** TEST 'Clang :: Tooling/clang-linker-wrapper-spirv-elf.cpp' FAILED ********************
Exit Code: 1

Command Output (stderr):
--
RUN: at line 4: mkdir -p /local/mnt/workspace/bots/hexagon-build-02/reverse-iteration/llvm.obj/tools/clang/test/Tooling/Output/clang-linker-wrapper-spirv-elf.cpp.tmp_tmp
+ mkdir -p /local/mnt/workspace/bots/hexagon-build-02/reverse-iteration/llvm.obj/tools/clang/test/Tooling/Output/clang-linker-wrapper-spirv-elf.cpp.tmp_tmp
RUN: at line 5: cd /local/mnt/workspace/bots/hexagon-build-02/reverse-iteration/llvm.obj/tools/clang/test/Tooling/Output/clang-linker-wrapper-spirv-elf.cpp.tmp_tmp
+ cd /local/mnt/workspace/bots/hexagon-build-02/reverse-iteration/llvm.obj/tools/clang/test/Tooling/Output/clang-linker-wrapper-spirv-elf.cpp.tmp_tmp
RUN: at line 6: /local/mnt/workspace/bots/hexagon-build-02/reverse-iteration/llvm.obj/bin/clang --driver-mode=g++ -fopenmp -fopenmp-targets=spirv64-intel -nogpulib -c -o /local/mnt/workspace/bots/hexagon-build-02/reverse-iteration/llvm.obj/tools/clang/test/Tooling/Output/clang-linker-wrapper-spirv-elf.cpp.tmp_clang-linker-wrapper-spirv-elf.o /local/mnt/workspace/bots/hexagon-build-02/reverse-iteration/llvm.src/clang/test/Tooling/clang-linker-wrapper-spirv-elf.cpp
+ /local/mnt/workspace/bots/hexagon-build-02/reverse-iteration/llvm.obj/bin/clang --driver-mode=g++ -fopenmp -fopenmp-targets=spirv64-intel -nogpulib -c -o /local/mnt/workspace/bots/hexagon-build-02/reverse-iteration/llvm.obj/tools/clang/test/Tooling/Output/clang-linker-wrapper-spirv-elf.cpp.tmp_clang-linker-wrapper-spirv-elf.o /local/mnt/workspace/bots/hexagon-build-02/reverse-iteration/llvm.src/clang/test/Tooling/clang-linker-wrapper-spirv-elf.cpp
clang: error: unable to execute command: Executable "llvm-spirv" doesn't exist!
clang: error: llvm-spirv command failed with exit code 1 (use -v to see invocation)

--

********************


```

</details>

https://github.com/llvm/llvm-project/pull/126098