Update V8 to r7427: Initial merge by git

As required by WebKit r82507

Change-Id: I7ae83ef3f689356043b4929255b7c1dd31d8c5df
diff --git a/src/d8-posix.cc b/src/d8-posix.cc
index 335bd2b..a7a4049 100644
--- a/src/d8-posix.cc
+++ b/src/d8-posix.cc
@@ -375,8 +375,10 @@
 // a parent process hangs on waiting while a child process is already a zombie.
 // See http://code.google.com/p/v8/issues/detail?id=401.
 #if defined(WNOWAIT) && !defined(ANDROID) && !defined(__APPLE__)
+#if !defined(__FreeBSD__)
 #define HAS_WAITID 1
 #endif
+#endif
 
 
 // Get exit status of child.