Update V8 to r4730 as required by WebKit r60469
diff --git a/src/mips/assembler-mips.cc b/src/mips/assembler-mips.cc
index 4a91624..d9617dc 100644
--- a/src/mips/assembler-mips.cc
+++ b/src/mips/assembler-mips.cc
@@ -34,6 +34,9 @@
 
 
 #include "v8.h"
+
+#if defined(V8_TARGET_ARCH_MIPS)
+
 #include "mips/assembler-mips-inl.h"
 #include "serialize.h"
 
@@ -1206,3 +1209,4 @@
 
 } }  // namespace v8::internal
 
+#endif  // V8_TARGET_ARCH_MIPS