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

[Petar Avramovic via llvm-commits]

https://github.com/petar-avramovic commented:

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

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