[llvm] [DAG] Remove OneUse restriction on sext when folding (shl (sext (add_nsw x, c1)), c2) (PR #68972)

[Craig Topper via llvm-commits]

topperc wrote:

Isn't this only profitable for RISC-V if the addi can be absorbed into a load/store address. Couldn't there still be other tests like the X86 case that would regress?

https://github.com/llvm/llvm-project/pull/68972