Merge v8_optimized_debug 1 and 2

src/vector.h

 // Copyright 2014 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_VECTOR_H_
 #define V8_VECTOR_H_
 
 #include <string.h>
 #include <algorithm>
 
@@ skipping 13 matching lines @@
     DCHECK(length == 0 || (length > 0 && data != NULL));
   }
 
   static Vector<T> New(int length) {
     return Vector<T>(NewArray<T>(length), length);
   }
 
   // Returns a vector using the same backing storage as this one,
   // spanning from and including 'from', to but not including 'to'.
   Vector<T> SubVector(int from, int to) {
-    SLOW_DCHECK(to <= length_);
+    DCHECK(0 <= from);
     SLOW_DCHECK(from < to);
-    DCHECK(0 <= from);
+    SLOW_DCHECK(static_cast<unsigned>(to) <= static_cast<unsigned>(length_));
     return Vector<T>(start() + from, to - from);
   }
 
   // Returns the length of the vector.
   int length() const { return length_; }
 
   // Returns whether or not the vector is empty.
   bool is_empty() const { return length_ == 0; }
 
   // Returns the pointer to the start of the data in the vector.
@@ skipping 130 matching lines @@
 
 inline Vector<char> MutableCStrVector(char* data, int max) {
   int length = StrLength(data);
   return Vector<char>(data, (length < max) ? length : max);
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_VECTOR_H_