C++1y: Allow aggregates to have default initializers.

Add a CXXDefaultInitExpr, analogous to CXXDefaultArgExpr, and use it both in
CXXCtorInitializers and in InitListExprs to represent a default initializer.

There's an additional complication here: because the default initializer can
refer to the initialized object via its 'this' pointer, we need to make sure
that 'this' points to the right thing within the evaluation.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@179958 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/CGExprComplex.cpp b/lib/CodeGen/CGExprComplex.cpp
index 5fc73aa..36f974a 100644
--- a/lib/CodeGen/CGExprComplex.cpp
+++ b/lib/CodeGen/CGExprComplex.cpp
@@ -182,6 +182,10 @@
   ComplexPairTy VisitCXXDefaultArgExpr(CXXDefaultArgExpr *DAE) {
     return Visit(DAE->getExpr());
   }
+  ComplexPairTy VisitCXXDefaultInitExpr(CXXDefaultInitExpr *DIE) {
+    CodeGenFunction::CXXDefaultInitExprScope Scope(CGF);
+    return Visit(DIE->getExpr());
+  }
   ComplexPairTy VisitExprWithCleanups(ExprWithCleanups *E) {
     CGF.enterFullExpression(E);
     CodeGenFunction::RunCleanupsScope Scope(CGF);