[MLIR][OpenMP] Refactor omp.target_allocmem to allow reuse, NFC#161861

skatrak wants to merge 1 commit intousers/skatrak/flang-generic-07-dealloc-pointllvm/llvm-project:users/skatrak/flang-generic-07-dealloc-pointfrom

users/skatrak/flang-generic-08-allocmem-refactorllvm/llvm-project:users/skatrak/flang-generic-08-allocmem-refactorCopy head branch name to clipboard