Update V8 to r4730 as required by WebKit r60469
diff --git a/src/arm/cpu-arm.cc b/src/arm/cpu-arm.cc
index d50c203..3d3e6ae 100644
--- a/src/arm/cpu-arm.cc
+++ b/src/arm/cpu-arm.cc
@@ -32,6 +32,8 @@
 
 #include "v8.h"
 
+#if defined(V8_TARGET_ARCH_ARM)
+
 #include "cpu.h"
 #include "macro-assembler.h"
 
@@ -136,3 +138,5 @@
 }
 
 } }  // namespace v8::internal
+
+#endif  // V8_TARGET_ARCH_ARM