Implement Mike Herrick's proposed noexcept mangling.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@164593 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/AST/ItaniumMangle.cpp b/lib/AST/ItaniumMangle.cpp
index afd425b5..3a16801 100644
--- a/lib/AST/ItaniumMangle.cpp
+++ b/lib/AST/ItaniumMangle.cpp
@@ -2412,7 +2412,6 @@
   case Expr::ExpressionTraitExprClass:
   case Expr::VAArgExprClass:
   case Expr::CXXUuidofExprClass:
-  case Expr::CXXNoexceptExprClass:
   case Expr::CUDAKernelCallExprClass:
   case Expr::AsTypeExprClass:
   case Expr::PseudoObjectExprClass:
@@ -2604,6 +2603,11 @@
     Out <<"_E";
     break;
 
+  case Expr::CXXNoexceptExprClass:
+    Out << "nx";
+    mangleExpression(cast<CXXNoexceptExpr>(E)->getOperand());
+    break;
+
   case Expr::UnaryExprOrTypeTraitExprClass: {
     const UnaryExprOrTypeTraitExpr *SAE = cast<UnaryExprOrTypeTraitExpr>(E);