[clang] [llvm] [VectorCombine] Trim low end of loads used in shufflevector rebroadcasts. (PR #149093)

[Matt Arsenault via cfe-commits]

================
@@ -4789,8 +4794,13 @@ bool VectorCombine::shrinkLoadForShuffles(Instruction &I) {
         return false;
 
       // Create new load of smaller vector.
+      Value *NewPtr =
+          LowOffset > 0u
+              ? Builder.CreateInBoundsPtrAdd(PtrOp, Builder.getInt32(LowOffset))
----------------
arsenm wrote:

This just moves the steps, use the ConstantInt of DL.getIndexType

https://github.com/llvm/llvm-project/pull/149093