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

[Min-Yih Hsu via llvm-commits]

mshockwave wrote:

> > Additionally, this file lacks vector versions of any of the shift tests. I'll look into introducing them.
> 
> According to the docs, RISC-V supports vectory types: https://llvm.org/docs/RISCV/RISCVVectorExtension.html. However, every time I try to write a trivial function test with a vector I get an error stating that RISC-V is unable to "lower" the arguments. I think the reason I can't use them has to do with the test running a version of RISC-V without the vector extension enabled. What should I change the `RUN` commands to in order to test `fshl` and `fshr` with vectors?

To enable vectors, you can `llc -mattr=+v ...`

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