[clang][AST] TextNodeDumper learned to dump NRVO candidates of return stmts

[aaron.ballman]

Can you add test coverage for the changes?

[strimo378]

Added test case

[strimo378]

@aaron.ballman Alright ... I managed to extend an existing test case

[aaron.ballman]

LGTM!

clang/include/clang/AST/TextNodeDumper.h

#include "clang/AST/AttrTextNodeDump.inc"
   void VisitPackTemplateArgument(const TemplateArgument &TA);
 
   void VisitIfStmt(const IfStmt *Node);
   void VisitSwitchStmt(const SwitchStmt *Node);
   void VisitWhileStmt(const WhileStmt *Node);
   void VisitLabelStmt(const LabelStmt *Node);
   void VisitGotoStmt(const GotoStmt *Node);
   void VisitCaseStmt(const CaseStmt *Node);
+  void VisitReturnStmt(const ReturnStmt *Node);
   void VisitCompoundStmt(const CompoundStmt *Node);
   void VisitConstantExpr(const ConstantExpr *Node);
   void VisitCallExpr(const CallExpr *Node);
   void VisitCXXOperatorCallExpr(const CXXOperatorCallExpr *Node);
   void VisitCastExpr(const CastExpr *Node);
   void VisitImplicitCastExpr(const ImplicitCastExpr *Node);
   void VisitDeclRefExpr(const DeclRefExpr *Node);
   void VisitSYCLUniqueStableNameExpr(const SYCLUniqueStableNameExpr *Node);

clang/lib/AST/TextNodeDumper.cpp

void TextNodeDumper::VisitGotoStmt(const GotoStmt *Node) {
   dumpPointer(Node->getLabel());
 }
 
 void TextNodeDumper::VisitCaseStmt(const CaseStmt *Node) {
   if (Node->caseStmtIsGNURange())
     OS << " gnu_range";
 }
 
+void clang::TextNodeDumper::VisitReturnStmt(const ReturnStmt *Node) {
+  if (const VarDecl *Cand = Node->getNRVOCandidate()) {
+    OS << " nrvo_candidate(";
+    dumpBareDeclRef(Cand);
+    OS << ")";
+  }
+}
+
 void TextNodeDumper::VisitConstantExpr(const ConstantExpr *Node) {
   if (Node->hasAPValueResult())
     AddChild("value",
              [=] { Visit(Node->getAPValueResult(), Node->getType()); });
 }
 
 void TextNodeDumper::VisitCallExpr(const CallExpr *Node) {
   if (Node->usesADL())