Really remove io support when dart:io is unsupported.

runtime/bin/main.cc

 // Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include <stdlib.h>
 #include <string.h>
 #include <stdio.h>
 
 #include "include/dart_api.h"
 #include "include/dart_tools_api.h"
 
 #include "bin/builtin.h"
 #include "bin/dartutils.h"
 #include "bin/directory.h"
 #include "bin/embedded_dart_io.h"
 #include "bin/eventhandler.h"
 #include "bin/extensions.h"
 #include "bin/file.h"
 #include "bin/isolate_data.h"
 #include "bin/log.h"
 #include "bin/platform.h"
 #include "bin/process.h"
 #include "bin/thread.h"
 #include "bin/utils.h"
 #include "bin/vmservice_impl.h"
 #include "platform/globals.h"
 #include "platform/hashmap.h"
 #include "platform/text_buffer.h"
+#if !defined(DART_PRECOMPILER)
 #include "zlib/zlib.h"
+#endif
 
 namespace dart {
 namespace bin {
 
 // vm_isolate_snapshot_buffer points to a snapshot for the vm isolate if we
 // link in a snapshot otherwise it is initialized to NULL.
 extern const uint8_t* vm_isolate_snapshot_buffer;
 
 // isolate_snapshot_buffer points to a snapshot for an isolate if we link in a
 // snapshot otherwise it is initialized to NULL.
@@ skipping 1657 matching lines @@
   Platform::Exit(Process::GlobalExitCode());
 }
 
 }  // namespace bin
 }  // namespace dart
 
 int main(int argc, char** argv) {
   dart::bin::main(argc, argv);
   UNREACHABLE();
 }