Fix build.

R=jkummerow@chromium.org
BUG=
TEST=

Review URL: https://chromiumcodereview.appspot.com/10829075

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@12220 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/conversions.h

@@ -29,6 +29,7 @@
 #define V8_CONVERSIONS_H_
 
 #include "utils.h"
+#include "double.h"
 
 namespace v8 {
 namespace internal {