Do not crash in the callgraph construction when encountering deleted function definitions.  Fixes <rdar://problem/11178609>.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@154081 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/CallGraph.cpp b/lib/Analysis/CallGraph.cpp
index eb3f3ef..01d6c41 100644
--- a/lib/Analysis/CallGraph.cpp
+++ b/lib/Analysis/CallGraph.cpp
@@ -125,7 +125,8 @@
 
   // Process all the calls by this function as well.
   CGBuilder builder(this, D, Node);
-  builder.Visit(D->getBody());
+  if (Stmt *Body = D->getBody())
+    builder.Visit(Body);
 }
 
 void CallGraph::addToCallGraph(TranslationUnitDecl *TU) {