[llvm] [GISel] Funnel shift combiner port from SelectionDAG ISel to GlobalISel (PR #135132)

[Axel Sorenson via llvm-commits]

axelcool1234 wrote:

> Additionally, this file lacks vector versions of any of the shift tests. I'll look into introducing them.

Does RISCV support vector types? Every time I try to write a trivial function test I get an error stating that RISCV is unable to "lower" the arguments. 

https://github.com/llvm/llvm-project/pull/135132