Implement instantiation of a few boring, simple expressions. I don't think these are testable yet, though.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@71953 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/AST/ExprCXX.cpp b/lib/AST/ExprCXX.cpp
index 8176db5..71617c4 100644
--- a/lib/AST/ExprCXX.cpp
+++ b/lib/AST/ExprCXX.cpp
@@ -309,3 +309,15 @@
   return &SubExpr + 1;
 }
 
+
+//===----------------------------------------------------------------------===//
+//  Cloners
+//===----------------------------------------------------------------------===//
+
+CXXBoolLiteralExpr* CXXBoolLiteralExpr::Clone(ASTContext &C) const {
+  return new (C) CXXBoolLiteralExpr(Value, getType(), Loc);
+}
+
+CXXNullPtrLiteralExpr* CXXNullPtrLiteralExpr::Clone(ASTContext &C) const {
+  return new (C) CXXNullPtrLiteralExpr(getType(), Loc);
+}