[llvm] [X86][GlobalISel] Enable G_SDIV/G_UDIV/G_SREM/G_UREM (PR #81615)

[Evgenii Kudriashov via llvm-commits]

e-kud wrote:

I want to admit that it was too harsh to replace all `mir` tests with `ll` tests. Returned and unified legalizer tests as @RKSimon suggested. 

@tschuett do you think we still need updated select tests? These tests won't be much different from the existing ones that check invalid MIR. I think that the best check of instruction selection is valid final assembly. But I don't mind to keep them if we see their usefulness. Before fix it was an assert in register allocator due to `SUBREG_TO_REG` misuse.

https://github.com/llvm/llvm-project/pull/81615