Remove grab-bag includes of v8.h from everywhere.

src/dtoa.h

 // Copyright 2011 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_DTOA_H_
 #define V8_DTOA_H_
 
+#include "src/vector.h"
+
 namespace v8 {
 namespace internal {
 
 enum DtoaMode {
   // Return the shortest correct representation.
   // For example the output of 0.299999999999999988897 is (the less accurate but
   // correct) 0.3.
   DTOA_SHORTEST,
   // Return a fixed number of digits after the decimal point.
   // For instance fixed(0.1, 4) becomes 0.1000
@@ skipping 35 matching lines @@
 // 'DoubleToAscii' expects the given buffer to be big enough to hold all digits
 // and a terminating null-character. In SHORTEST-mode it expects a buffer of
 // at least kBase10MaximalLength + 1. Otherwise, the size of the output is
 // limited to requested_digits digits plus the null terminator.
 void DoubleToAscii(double v, DtoaMode mode, int requested_digits,
                    Vector<char> buffer, int* sign, int* length, int* point);
 
 } }  // namespace v8::internal
 
 #endif  // V8_DTOA_H_