Make sure to insert the primary base in the set :)

llvm-svn: 97339
diff --git a/clang/lib/CodeGen/CGVtable.cpp b/clang/lib/CodeGen/CGVtable.cpp
index b7f8fe77..d5d2215 100644
--- a/clang/lib/CodeGen/CGVtable.cpp
+++ b/clang/lib/CodeGen/CGVtable.cpp
@@ -1512,6 +1512,9 @@
              "Primary base should always be at offset 0!");
     }
     
+    if (!PrimaryBases.insert(PrimaryBase))
+      assert(false && "Found a duplicate primary base!");
+
     RD = PrimaryBase;
   }