Add assert.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@47641 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/AsmParser/llvmAsmParser.y b/lib/AsmParser/llvmAsmParser.y
index b7b4009..5a824ae 100644
--- a/lib/AsmParser/llvmAsmParser.y
+++ b/lib/AsmParser/llvmAsmParser.y
@@ -2581,8 +2581,8 @@
 BBTerminatorInst : 
   RET ReturnedVal  { // Return with a result...
     ValueList &VL = *$2;
-    if (!VL.empty())
-      $$ = new ReturnInst(&VL[0], VL.size());
+    assert(!VL.empty() && "Invalid ret operands!");
+    $$ = new ReturnInst(&VL[0], VL.size());
     delete $2;
     CHECK_FOR_ERROR
   }