[llvm] [AMDGPU] Add flag to prevent reruns of LowerModuleLDS (PR #129520)

[Shilei Tian via llvm-commits]

shiltian wrote:

The pass runs in the full LTO post-link pipeline, and there are cases where post-link optimization may run multiple times. For example, in the OpenMP use case, the OpenMP device runtime is optimized in a post-link stage and gets the module flag. When it is later linked into user code, the module flag is included, preventing the pass from running again on the user code.

https://github.com/llvm/llvm-project/pull/129520