Update V8 to r5675 as required by WebKit r70209

Change-Id: Ib10adb470d41ca8c109ead5fc893b880e18d489f
diff --git a/src/log-utils.h b/src/log-utils.h
index 8889f1b..ffea928 100644
--- a/src/log-utils.h
+++ b/src/log-utils.h
@@ -132,6 +132,7 @@
     size_t rv = fwrite(msg, 1, length, output_handle_);
     ASSERT(static_cast<size_t>(length) == rv);
     USE(rv);
+    fflush(output_handle_);
     return length;
   }
 
@@ -151,6 +152,9 @@
   // mutex_ should be acquired before using output_handle_ or output_buffer_.
   static FILE* output_handle_;
 
+  // Used when low-level profiling is active to save code object contents.
+  static FILE* output_code_handle_;
+
   static LogDynamicBuffer* output_buffer_;
 
   // Size of dynamic buffer block (and dynamic buffer initial size).
@@ -170,6 +174,7 @@
   // mutex_ should be acquired before using it.
   static char* message_buffer_;
 
+  friend class Logger;
   friend class LogMessageBuilder;
   friend class LogRecordCompressor;
 };