[llvm] [mlir] [mlir][gpu] Change GPU modules to globals (PR #135478)

[Valentin Clement バレンタイン クレメン via llvm-commits]

clementval wrote:

> I'm sorry this change is causing trouble for you. I'm not sure now, can you work with the current state or do you prefer to move the module global+ctor/dtor creation back to createKernelLaunch?

We can live with it and we already have a workaround  but I think that having this with `createKernelLaunch` makes more sense.  

https://github.com/llvm/llvm-project/pull/135478