[clang] [flang] [mlir] [flang][flang-driver][mlir][OpenMP] atomic control support (PR #143441)

[Anchu Rajendran S via cfe-commits]

anchuraj wrote:

> Please remove 'amdgpu' from variable and function names. These options may be useful for other targets as well.

Thank you for the review. I have updated. 

https://github.com/llvm/llvm-project/pull/143441