[llvm] [X86][GlobalISel] Enable nest arguments (PR #165173)

[Evgenii Kudriashov via llvm-commits]

e-kud wrote:

> LGTM - although I don't have much experience with nest / trampoline attributes

Unfortunately I'm not very experienced with them as well. I only have the fact that fortran benchmarks compiled with this patch are passing and validated (the patch increases the portion of function selected by GlobalISel)

https://github.com/llvm/llvm-project/pull/165173