[regexp] Fix off-by-one in CharacterRange::Negate.

src/regexp/jsregexp.h

 // Copyright 2012 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.
 
 #ifndef V8_REGEXP_JSREGEXP_H_
 #define V8_REGEXP_JSREGEXP_H_
 
 #include "src/allocation.h"
 #include "src/assembler.h"
 #include "src/regexp/regexp-ast.h"
@@ skipping 250 matching lines @@
 // A mapping from integers, specified as ranges, to a set of integers.
 // Used for mapping character ranges to choices.
 class DispatchTable : public ZoneObject {
  public:
   explicit DispatchTable(Zone* zone) : tree_(zone) { }
 
   class Entry {
    public:
     Entry() : from_(0), to_(0), out_set_(NULL) { }
     Entry(uc32 from, uc32 to, OutSet* out_set)
-        : from_(from), to_(to), out_set_(out_set) {}
+        : from_(from), to_(to), out_set_(out_set) {
+      DCHECK(from <= to);
+    }
     uc32 from() { return from_; }
     uc32 to() { return to_; }
     void set_to(uc32 value) { to_ = value; }
     void AddValue(int value, Zone* zone) {
       out_set_ = out_set_->Extend(value, zone);
     }
     OutSet* out_set() { return out_set_; }
    private:
     uc32 from_;
     uc32 to_;
@@ skipping 1299 matching lines @@
   static const int kStringOffset = 0;
   static const int kPatternOffset = 1;
   static const int kArrayOffset = 2;
   static const int kLastMatchOffset = 3;
 };
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_REGEXP_JSREGEXP_H_