[llvm] [AMDGPU]Optimize SGPR spills (PR #93668)

[Vikash Gupta via llvm-commits]

vg0204 wrote:

> [res.new.zip](https://github.com/user-attachments/files/15914966/res.new.zip) bc and assembly without debug info are attached. pls use [4b9112e](https://github.com/llvm/llvm-project/commit/4b9112e88a998ce620e4683548f2afd17cc5fe95) clang and the above mentioned command to get assembly and compare with the attached one to make sure they are the same.

The assembly generated is having debug info, so it is same as the assmble shared previously, but not the one present in res.new.zip!

https://github.com/llvm/llvm-project/pull/93668