[llvm] [DAGCombine] Remove oneuse restrictions for RISCV in folding (shl (add_nsw x, c1)), c2) and folding (shl(sext(add x, c1)), c2) in some scenarios (PR #101294)

[Min-Yih Hsu via llvm-commits]

mshockwave wrote:

> The local branch is updated to the latest version

Right, please avoid rebasing the local branch unless necessary, per LLVM's code review policy: https://llvm.org/docs/GitHub.html#rebasing-pull-requests-and-force-pushes

https://github.com/llvm/llvm-project/pull/101294