[CPU] Suppress C4065 warning in SyscallHandler.

src/xenia/cpu/ppc/ppc_frontend.cc

@@ -86,6 +86,7 @@ void SyscallHandler(PPCContext* ppc_context, void* arg0, void* arg1) {
       assert_unhandled_case(syscall_number);
       XELOGE("Unhandled syscall {}!", syscall_number);
       break;
+#pragma warning(suppress : 4065)
   }
 }