Update V8 to r4730 as required by WebKit r60469
diff --git a/src/mips/macro-assembler-mips.cc b/src/mips/macro-assembler-mips.cc
index c276af5..e096028 100644
--- a/src/mips/macro-assembler-mips.cc
+++ b/src/mips/macro-assembler-mips.cc
@@ -29,6 +29,8 @@
 
 #include "v8.h"
 
+#if defined(V8_TARGET_ARCH_MIPS)
+
 #include "bootstrapper.h"
 #include "codegen-inl.h"
 #include "debug.h"
@@ -1321,3 +1323,4 @@
 
 } }  // namespace v8::internal
 
+#endif  // V8_TARGET_ARCH_MIPS