SCEVExpander: give new insts a name that identifies the reponsible pass.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@133992 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Transforms/Scalar/IndVarSimplify.cpp

@@ -1169,7 +1169,7 @@ bool IndVarSimplify::runOnLoop(Loop *L, LPPassManager &LPM) {
   const SCEV *BackedgeTakenCount = SE->getBackedgeTakenCount(L);
 
   // Create a rewriter object which we'll use to transform the code with.
-  SCEVExpander Rewriter(*SE);
+  SCEVExpander Rewriter(*SE, "indvars");
 
   // Eliminate redundant IV users.
   //