fix encoding of BB names in the symtab

llvm-svn: 36704
diff --git a/llvm/lib/Bitcode/Writer/ValueEnumerator.cpp b/llvm/lib/Bitcode/Writer/ValueEnumerator.cpp
index fab1d9c..4d3f0fd 100644
--- a/llvm/lib/Bitcode/Writer/ValueEnumerator.cpp
+++ b/llvm/lib/Bitcode/Writer/ValueEnumerator.cpp
@@ -180,8 +180,8 @@
             isa<InlineAsm>(*OI))
           EnumerateValue(*OI);
       }
-    ValueMap[BB] = BasicBlocks.size();
     BasicBlocks.push_back(BB);
+    ValueMap[BB] = BasicBlocks.size();
   }
   
   FirstInstID = Values.size();