adjust a couple xforms to work with null bb's in BlockAddress.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@85680 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Utils/ValueMapper.cpp b/lib/Transforms/Utils/ValueMapper.cpp
index 39331d7..7929eb9 100644
--- a/lib/Transforms/Utils/ValueMapper.cpp
+++ b/lib/Transforms/Utils/ValueMapper.cpp
@@ -113,8 +113,13 @@
   
   if (BlockAddress *BA = dyn_cast<BlockAddress>(C)) {
     Function *F = cast<Function>(MapValue(BA->getFunction(), VM));
-    BasicBlock *BB = cast_or_null<BasicBlock>(MapValue(BA->getBasicBlock(),VM));
-    return VM[V] = BlockAddress::get(F, BB ? BB : BA->getBasicBlock());
+    BasicBlock *BB = 0;
+    if (BA->getBasicBlock()) {
+      BB = cast_or_null<BasicBlock>(MapValue(BA->getBasicBlock(),VM));
+      BB = BB ? BB : BA->getBasicBlock();
+    }
+    
+    return VM[V] = BlockAddress::get(F, BB);
   }
   
   llvm_unreachable("Unknown type of constant!");