Revert of [regexp] implement character classes for unicode regexps.

src/regexp/regexp-ast.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/ostreams.h"
 #include "src/regexp/regexp-ast.h"
 
 namespace v8 {
 namespace internal {
 
@@ skipping 154 matching lines @@
   for (int i = 0; i < that->nodes()->length(); i++) {
     os_ << " ";
     that->nodes()->at(i)->Accept(this, data);
   }
   os_ << ")";
   return NULL;
 }
 
 
 void RegExpUnparser::VisitCharacterRange(CharacterRange that) {
-  os_ << AsUC32(that.from());
+  os_ << AsUC16(that.from());
   if (!that.IsSingleton()) {
-    os_ << "-" << AsUC32(that.to());
+    os_ << "-" << AsUC16(that.to());
   }
 }
 
 
 void* RegExpUnparser::VisitCharacterClass(RegExpCharacterClass* that,
                                           void* data) {
   if (that->is_negated()) os_ << "^";
   os_ << "[";
   for (int i = 0; i < that->ranges(zone_)->length(); i++) {
     if (i > 0) os_ << " ";
@@ skipping 140 matching lines @@
     int node_min_match = node->min_match();
     min_match_ = IncreaseBy(min_match_, node_min_match);
     int node_max_match = node->max_match();
     max_match_ = IncreaseBy(max_match_, node_max_match);
   }
 }
 
 
 }  // namespace internal
 }  // namespace v8