[clang] [OpenMP][OMPIRBuilder] Add support to omp target parallel (PR #67000)

[Dominik Adamski via cfe-commits]

DominikAdamski wrote:

@shraiysh `ParallelSimpleGPU` tests only the LLVM IR for the target device. `kmpc_parallel_51` is the function which needs to be executed on the GPU. The aim of this patch is to add GPU code generation for `omp target parallel pragma`.

https://github.com/llvm/llvm-project/pull/67000