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

[Matt Arsenault via llvm-commits]

arsenm wrote:

> They show the SUBREG_TO_REG, but SUBREG_TO_REG is often misunderstood and there's nothing that can check that is correctly used.

We really should just remove SUBREG_TO_REG, it's impossible to use it correctly. My patch to hack around it in the coalescer is currently stuck on it's 5th or 6th revert due to unrelated issues it happens to hit 

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