Remove debugging assert.

Found by Richard Smith in post-commit review of r167906.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@167911 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/AST/ItaniumMangle.cpp b/lib/AST/ItaniumMangle.cpp
index fc61d88..7509d96 100644
--- a/lib/AST/ItaniumMangle.cpp
+++ b/lib/AST/ItaniumMangle.cpp
@@ -1127,9 +1127,6 @@
       break;
     }
 
-    //assert(cast<RecordDecl>(RD)->isAnonymousStructOrUnion() && "Don't mangle unnamed things as "
-    //  "anonymous things");
-        
     // Get a unique id for the anonymous struct.
     uint64_t AnonStructId = Context.getAnonymousStructId(TD);