[llvm] [AMDGPU] Add amdgpu-lower-exec-sync pass to lower named-barrier globals (PR #165692)

[Sameer Sahasrabuddhe via llvm-commits]

ssahasra wrote:

> I don't see the changes that remove the logic from LowerModuleLDS? Are they missing?
> 
> EDIT: Ah I see, they're in the next PR that enables the pass. Please update the PR description to reflect that

I don't really see why we need three separate commits for this. It's just existing code getting rebundled into a pass, and that pass is being enabled by default in its new intended place. All this _should_ be done as a single change. This kind of split can hide complexity and errors. With a single change, if anything breaks, then either things were not as simple as they seem, or errors were introduced. But it will all be trackable to this one change.

https://github.com/llvm/llvm-project/pull/165692