Reapply r139759. Disable IV rewriting by default. See PR10916.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@139842 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Scalar/IndVarSimplify.cpp b/lib/Transforms/Scalar/IndVarSimplify.cpp
index b5500de..e240c42 100644
--- a/lib/Transforms/Scalar/IndVarSimplify.cpp
+++ b/lib/Transforms/Scalar/IndVarSimplify.cpp
@@ -60,7 +60,7 @@
 
 namespace llvm {
   cl::opt<bool> EnableIVRewrite(
-    "enable-iv-rewrite", cl::Hidden, cl::init(true),
+    "enable-iv-rewrite", cl::Hidden,
     cl::desc("Enable canonical induction variable rewriting"));
 
   // Trip count verification can be enabled by default under NDEBUG if we