Really remove io support when dart:io is unsupported.

runtime/bin/platform_linux.cc

Index: runtime/bin/platform_linux.cc
diff --git a/runtime/bin/platform_linux.cc b/runtime/bin/platform_linux.cc
index c6dc3ccb15bcc74aa14208ac94ef7c111fa6d510..054ff6dc8257ece6e333511663634af6371f07cd 100644
--- a/runtime/bin/platform_linux.cc
+++ b/runtime/bin/platform_linux.cc
@@ -5,7 +5,6 @@
 #include "platform/globals.h"
 #if defined(TARGET_OS_LINUX)
 
-#include "bin/file.h"
 #include "bin/platform.h"
 
 #include <signal.h>  // NOLINT
@@ -13,10 +12,16 @@
 #include <unistd.h>  // NOLINT
 
 #include "bin/fdutils.h"
+#include "bin/file.h"
 
 namespace dart {
 namespace bin {
 
+const char* Platform::executable_name_ = NULL;
+char* Platform::resolved_executable_name_ = NULL;
+int Platform::script_index_ = 1;
+char** Platform::argv_ = NULL;
+
 bool Platform::Initialize() {
   // Turn off the signal handler for SIGPIPE as it causes the process
   // to terminate on writing to a closed pipe. Without the signal