Resolve the executable path on Mac OS when sym-linked

tests/standalone/io/platform_executable_test.dart

 // 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.
 //
 // Process test program to test process communication.
 
 library PlatformExecutableTest;
 
 import "dart:io";
 
@@ skipping 89 matching lines @@
   link.createSync(exeFile.parent.path);
 
   //print('*** Path points to a sym-linked SDK dir');
   verify(platformExeName, altPath: link.path);
 }
 
 void testPathToSDKDir() {
   var exeFile = new File(Platform.executable);
   var binDirPath = exeFile.parent.path;
 
   //print('*** Running with PATH env set to environment - fixed in 16994 - thanks!');

[kustermann, 2015/06/11 18:34:27]

long line

[Søren Gjesse, 2015/06/12 07:24:24]

I removed all the print in comments in the file.

   verify(platformExeName, altPath: binDirPath);
 }
 
 void withTempDir(void test(Directory dir)) {
   var tempDir = Directory.systemTemp.createTempSync('dart.sdk.test.');
   try {
     test(tempDir);
   } finally {
     tempDir.deleteSync(recursive: true);
   }
 }
 
 String get platformExeName {
   var raw = new Uri.file(Platform.executable);
   return raw.pathSegments.last;
 }
 
 String get scriptPath => Platform.script.toFilePath();
 
 void main() {
   if (Platform.environment.containsKey(_SCRIPT_KEY)) {
     print(Platform.executable);
     return;
   }
 
   testDartExecShouldNotBeInCurrentDir();
   testShouldSucceedWithSourcePlatformExecutable(); /// 00: ok
-  withTempDir(testExeSymLinked); /// 01: ok
+  // dart:io does not support linking to files in Windows.
+  if (!Platform.isWindows) {
+    withTempDir(testExeSymLinked); /// 01: ok
+  }
   withTempDir(testExeDirSymLinked); /// 02: ok
   testPathToSDKDir(); /// 03: ok
   withTempDir(testPathPointsToSymLinkedSDKPath); /// 04: ok
-  withTempDir(testPathToDirWithExeSymLinked); /// 05: ok
+  // dart:io does not support linking to files in Windows.
+  if (!Platform.isWindows) {
+    withTempDir(testPathToDirWithExeSymLinked); /// 05: ok
+  }
   testShouldSucceedWithEmptyPathEnvironment(); /// 06: ok
 }