[llvm-branch-commits] [llvm] release/18.x: [DAGCombiner] In mergeTruncStore, make sure we aren't storing shifted in bits. (#90939) (PR #91038)

[Tom Stellard via llvm-branch-commits]

tstellar wrote:

@topperc Do you have any strong objections to backporting this?  This looks small to me and I think it's OK to fix long-standing bugs.

https://github.com/llvm/llvm-project/pull/91038