Fix an MSVC warning.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@114184 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/MC/MCParser/AsmParser.cpp b/lib/MC/MCParser/AsmParser.cpp
index 5de2150..c5d2aa0 100644
--- a/lib/MC/MCParser/AsmParser.cpp
+++ b/lib/MC/MCParser/AsmParser.cpp
@@ -616,6 +616,9 @@
     return MCBinaryExpr::Create(BE->getOpcode(), LHS, RHS, getContext());
   }
   }
+
+  assert(0 && "Invalid expression kind!");
+  return 0;
 }
 
 /// ParseExpression - Parse an expression and return it.