Add NullStmt::Clone and use it

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@71823 91177308-0d34-0410-b5e6-96231b3b80d8

include/clang/AST/Stmt.h

@@ -290,6 +290,8 @@ public:
   /// \brief Build an empty null statement.
   explicit NullStmt(EmptyShell Empty) : Stmt(NullStmtClass, Empty) { }
 
+  NullStmt* Clone(ASTContext &C) const;
+
   SourceLocation getSemiLoc() const { return SemiLoc; }
   void setSemiLoc(SourceLocation L) { SemiLoc = L; }
 

lib/AST/Stmt.cpp

@@ -98,6 +98,10 @@ bool Stmt::CollectingStats(bool enable) {
   return StatSwitch;
 }
 
+NullStmt* NullStmt::Clone(ASTContext &C) const {
+  return new (C) NullStmt(SemiLoc);
+}
+
 void CompoundStmt::setStmts(ASTContext &C, Stmt **Stmts, unsigned NumStmts) {
   if (this->Body)
     C.Deallocate(Body);

lib/Sema/SemaTemplateInstantiateExpr.cpp

@@ -480,7 +480,7 @@ Sema::OwningStmtResult TemplateStmtInstantiator::VisitDeclStmt(DeclStmt *S) {
 }
 
 Sema::OwningStmtResult TemplateStmtInstantiator::VisitNullStmt(NullStmt *S) {
-  return SemaRef.Owned(new (SemaRef.Context) NullStmt(S->getSemiLoc()));
+  return SemaRef.Owned(S->Clone(SemaRef.Context));
 }
 
 Sema::OwningStmtResult TemplateStmtInstantiator::VisitLabelStmt(LabelStmt *S) {