[APInt] Use operator<<= instead of shl where possible. NFC

llvm-svn: 301103
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp b/llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp
index 2f6e411..c5812ab 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp
@@ -1562,7 +1562,7 @@
         for (unsigned Lane = 0; Lane != NumLanes; ++Lane) {
           APInt LaneElts = OpUndefElts.lshr(InnerVWidthPerLane * Lane);
           LaneElts = LaneElts.getLoBits(InnerVWidthPerLane);
-          LaneElts = LaneElts.shl(InnerVWidthPerLane * (2 * Lane + OpNum));
+          LaneElts <<= InnerVWidthPerLane * (2 * Lane + OpNum);
           UndefElts |= LaneElts;
         }
       }