[clang] [llvm] [Clang][OpenMP] Fix mapping of arrays of structs with members with mappers (PR #142511)

[Abhinav Gaba via llvm-commits]

abhinavgaba wrote:

Thanks, Alexey!

@sarnex, could you please help merge this? Windows build/test reports some "Slowed tests" that are Driver/Architecture specific, and not related to this change.

```
Slowest Tests:
--------------------------------------------------------------------------
109.56s: Clang :: Driver/fsanitize.c
46.84s: Clang :: Driver/hip-options.hip
46.77s: Clang :: Driver/hexagon-toolchain-elf.c
37.78s: Clang :: Driver/openmp-offload-gpu.c
37.05s: Clang :: Driver/mips-fsf.cpp
36.74s: Clang :: Driver/fopenmp.c
34.33s: Clang :: Driver/hip-device-libs.hip
34.14s: Clang :: Driver/x86-target-features.c
33.15s: Clang :: Driver/cuda-options.cu
32.20s: Clang :: Driver/amdgpu-mcpu.cl
31.36s: Clang :: Driver/darwin-ld.c
30.76s: Clang :: Driver/sanitizer-ld.c
29.44s: Clang :: Driver/mips-as.c
29.12s: Clang :: Driver/cuda-detect.cu
24.74s: Clang :: CodeGen/AArch64/sve-intrinsics/acle_sve_reinterpret.c
24.45s: Clang :: Driver/hip-cuid.hip
24.34s: Clang :: Driver/fsanitize-coverage.c
23.92s: Clang :: Driver/cuda-arch-translation.cu
23.84s: Clang :: Driver/hip-link-bundle-archive.hip
23.76s: Clang :: Driver/clang-offload-bundler.c
```

https://github.com/llvm/llvm-project/pull/142511