Fix the warnings issue during Scintilla's compiling

Remove std::iterator from Boost Regex search code:
std::iterator was deprecated in C++17.
Remove it to fix the warnings and avoid other issues.

Fix #10035, close #10036

boostregex/AnsiDocumentIterator.h

@@ -1,13 +1,35 @@
-#ifndef ANSIDOCUMENTITERATOR_H_12481491281240
+// This file is part of Notepad++ project
+// Copyright (C) 2021 Notepad++ authors.
+
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// at your option any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+#ifndef ANSIDOCUMENTITERATOR_H_12481491281240
 #define ANSIDOCUMENTITERATOR_H_12481491281240
 
 #include "Position.h"
 
 namespace Scintilla {
 
-class AnsiDocumentIterator : public std::iterator<std::bidirectional_iterator_tag, char>
+class AnsiDocumentIterator
 {
 public:
+	using iterator_category = std::bidirectional_iterator_tag;
+	using value_type = char;
+	using difference_type = ptrdiff_t;
+	using pointer = char*;
+	using reference = char&;
+
 	AnsiDocumentIterator() {};
 
 	AnsiDocumentIterator(Document* doc, Sci::Position pos, Sci::Position end) :

boostregex/BoostRegExSearch.cxx

@@ -10,7 +10,6 @@
  */
 
 #include <stdlib.h>
-#include <iterator> 
 #include <vector>
 #include <memory>
 #include <string_view>

boostregex/UTF8DocumentIterator.cxx

@@ -1,6 +1,20 @@
-#include "UTF8DocumentIterator.h"
+// This file is part of Notepad++ project
+// Copyright (C) 2021 Notepad++ authors.
 
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// at your option any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
 
+#include "UTF8DocumentIterator.h"
 #include <string_view>
 #include <stdexcept>
 
@@ -9,8 +23,6 @@
 #include "Scintilla.h"
 #include "Platform.h"
 
-
-
 #include "CharacterCategory.h"
 #include "Position.h"
 #include "SplitVector.h"

boostregex/UTF8DocumentIterator.h

@@ -1,8 +1,23 @@
-#ifndef UTF8DOCUMENTITERATOR_H_3452843291318441149
+// This file is part of Notepad++ project
+// Copyright (C) 2021 Notepad++ authors.
+
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// at your option any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License
+// along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+#ifndef UTF8DOCUMENTITERATOR_H_3452843291318441149
 #define UTF8DOCUMENTITERATOR_H_3452843291318441149
 
 #include <stdlib.h>
-#include <iterator>
 #include <vector>
 #include <memory>
 #include "Position.h"
@@ -11,9 +26,15 @@ namespace Scintilla {
 
 class Document;
 
-class UTF8DocumentIterator : public std::iterator<std::bidirectional_iterator_tag, wchar_t>
+class UTF8DocumentIterator
 {
 public:
+	using iterator_category = std::bidirectional_iterator_tag;
+	using value_type = wchar_t;
+	using difference_type = ptrdiff_t;
+	using pointer = wchar_t*;
+	using reference = wchar_t&;
+
 	UTF8DocumentIterator() {};
 
 	UTF8DocumentIterator(Document* doc, Sci::Position pos, Sci::Position end);