[llvm] [GlobalISel][ARM] Legalization of G_CONSTANT using constant pool (PR #98308)

[Serge Pavlov via llvm-commits]

spavloff wrote:

> Neutral version: This PR lowers to constant pool loads if:
> 
> ```
> if (ConstantMaterializationCost(ImmVal, ST) > 2 &&
>         !ST->genExecuteOnly())
> ```
> 
> using the standard legalizer tools.
> 
> #96225 does the same manually in the selector pass.

Not sure I understand the proposed solution. This condition checks the value of immediate operand but the Legalizer makes decision based on types only, no?

https://github.com/llvm/llvm-project/pull/98308