PR9604; try to deal with RAUW updates correctly in the AST.  I'm not convinced
it's completely safe to cache the AST across LICM runs even with this fix,
but this fix can't hurt.

llvm-svn: 129198
diff --git a/llvm/lib/Analysis/AliasSetTracker.cpp b/llvm/lib/Analysis/AliasSetTracker.cpp
index 3a46976..2ed6949 100644
--- a/llvm/lib/Analysis/AliasSetTracker.cpp
+++ b/llvm/lib/Analysis/AliasSetTracker.cpp
@@ -602,6 +602,10 @@
   // this now dangles!
 }
 
+void AliasSetTracker::ASTCallbackVH::allUsesReplacedWith(Value *V) {
+  AST->copyValue(getValPtr(), V);
+}
+
 AliasSetTracker::ASTCallbackVH::ASTCallbackVH(Value *V, AliasSetTracker *ast)
   : CallbackVH(V), AST(ast) {}