Put back dump() without a default argument, "because debuggers don't usually respect default arguments".

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@160788 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/include/clang/AST/DeclBase.h b/include/clang/AST/DeclBase.h
index b304f1f..ac2cc9e 100644
--- a/include/clang/AST/DeclBase.h
+++ b/include/clang/AST/DeclBase.h
@@ -857,8 +857,12 @@
   static void printGroup(Decl** Begin, unsigned NumDecls,
                          raw_ostream &Out, const PrintingPolicy &Policy,
                          unsigned Indentation = 0);
-  LLVM_ATTRIBUTE_USED void dump(raw_ostream &Out = llvm::errs()) const;
-  LLVM_ATTRIBUTE_USED void dumpXML(raw_ostream &OS = llvm::errs()) const;
+  // Debuggers don't usually respect default arguments.
+  LLVM_ATTRIBUTE_USED void dump() const { dump(llvm::errs()); }
+  void dump(raw_ostream &Out) const;
+  // Debuggers don't usually respect default arguments.
+  LLVM_ATTRIBUTE_USED void dumpXML() const { dumpXML(llvm::errs()); }
+  void dumpXML(raw_ostream &OS) const;
 
 private:
   void setAttrsImpl(const AttrVec& Attrs, ASTContext &Ctx);