[llvm] [AMDGPU][GlobalISel] Assign bank to vregs created by RegBankCombiner (PR #216270)

[Petar Avramovic via llvm-commits]

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

Really not sure about this one, and how tryCombineAllImpl is meant to be used.
+ @Pierre-vh to take a look. 

https://github.com/llvm/llvm-project/pull/216270