[OpenMP][libomp] Add transparent task flag bit to kmp_tasking_flags (#168873)
Clang is adding support for the new `OpenMP transparent` clause on
`task` and `taskloop` directives.
The parsing and semantic handling for this clause is introduced in
https://github.com/llvm/llvm-project/pull/166810 .
To allow the compiler to communicate this clause to the `OpenMP`
runtime, a dedicated bit in `kmp_tasking_flags` is required.
This patch adds a new compiler-reserved bit `transparent` to the`
kmp_tasking_flags` structure.