[regexp] allow loose matching for property names.

src/regexp/regexp-parser.cc

 // Copyright 2016 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/regexp/regexp-parser.h"
 
 #include "src/char-predicates-inl.h"
 #include "src/factory.h"
 #include "src/isolate.h"
 #include "src/objects-inl.h"
@@ skipping 822 matching lines @@
     }
     Reset(start);
   }
   return result;
 }
 
 ZoneList<CharacterRange>* RegExpParser::ParsePropertyClass() {
 #ifdef V8_I18N_SUPPORT
   ZoneList<char> property_name(0, zone());
   if (current() == '{') {
-    for (Advance(); IsAlpha(current()); Advance()) {
+    for (Advance(); current() != '}'; Advance()) {
+      if (!has_next()) return nullptr;
       property_name.Add(static_cast<char>(current()), zone());
     }
-    if (current() != '}') return nullptr;
-  } else if (IsAlpha(current())) {
+  } else if (current() != kEndMarker) {
     property_name.Add(static_cast<char>(current()), zone());
   } else {
     return nullptr;
   }
   Advance();
   property_name.Add(0, zone());  // null-terminate string.
 
   // Property names are defined in unicode database files. For aliases of
   // these property names, see PropertyValueAliases.txt.
   UProperty kPropertyClasses[] = {
@@ skipping 592 matching lines @@
     return false;
   }
   terms_.Add(new (zone()) RegExpQuantifier(min, max, quantifier_type, atom),
              zone());
   LAST(ADD_TERM);
   return true;
 }
 
 }  // namespace internal
 }  // namespace v8