[llvm] [RISCV] Porting hasAllNBitUsers to RISCV GISel for instruction select (PR #124678)

[Luke Quinn via llvm-commits]

lquinn2015 wrote:

I wanted 2 points of feed back here 

1) there is no Recursion limit available in GISel like there is in SelectionDag but I was unsure of where to put that in the CodeGen/GlobalIsel headers

2) I am unsure how to check from a MachineOperand if it is a vector operation in GlobalISel I think I am missing a operation. Reguardless of doing that check the following code should default to failure for selected Vector type instructions since there opcodes are not enumerated. I think its better to stage out the Vector pseudo part as well. 

https://github.com/llvm/llvm-project/pull/124678