Revert my user-defined literal commits - r1124{58,60,67} pending
some issues being sorted out.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@112493 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/AST/ExprConstant.cpp b/lib/AST/ExprConstant.cpp
index d067668..14cbbaf 100644
--- a/lib/AST/ExprConstant.cpp
+++ b/lib/AST/ExprConstant.cpp
@@ -2423,8 +2423,7 @@
   case Expr::UnaryTypeTraitExprClass:
     return NoDiag();
   case Expr::CallExprClass:
-  case Expr::CXXOperatorCallExprClass:
-  case Expr::UDLiteralExprClass: {
+  case Expr::CXXOperatorCallExprClass: {
     const CallExpr *CE = cast<CallExpr>(E);
     if (CE->isBuiltinCall(Ctx))
       return CheckEvalInICE(E, Ctx);