[llvm] [AMDGPU][GISel] Add RegBankLegalize support for G_SI_CALL (PR #165747)

[Chinmay Deshpande via llvm-commits]

chinmaydd wrote:

> Are there any end to end .ll tests left then? Maybe add one you used to generate mir test as .ll test

Would you not consider the `irtranslator-*` tests as end-to-end ? I added the MIR test since none of existing ones test the waterfall loop.

https://github.com/llvm/llvm-project/pull/165747