Add AssertingVH which makes PR7647 break consistently.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@108401 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/InstructionSimplify.cpp b/lib/Analysis/InstructionSimplify.cpp
index dbefc2d..0efe183 100644
--- a/lib/Analysis/InstructionSimplify.cpp
+++ b/lib/Analysis/InstructionSimplify.cpp
@@ -443,7 +443,9 @@
   // FromHandle - This keeps a weakvh on the from value so that we can know if
   // it gets deleted out from under us in a recursive simplification.
   WeakVH FromHandle(From);
-  
+  // Double-check that To isn't deleted.
+  AssertingVH<> CheckedTo = To;
+
   while (!From->use_empty()) {
     // Update the instruction to use the new value.
     Use &U = From->use_begin().getUse();