Revert change to Platform.excutable and add Platform.resolvedExecutable

tests/standalone/io/platform_resolved_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 17 matching lines @@
 
   if (processResult.exitCode != 0) {
     throw 'Error with process\n'
           '$scriptPath'
           'Exit code: ${processResult.exitCode}\n'
           '   STDOUT: ${processResult.stdout}\n'
           '   STDERR: ${processResult.stderr}\n';
   }
 
   var result = processResult.stdout.trim();
-  expectEquals(Platform.executable, result);
+  expectEquals(Platform.resolvedExecutable, result);
 }
 
 void testDartExecShouldNotBeInCurrentDir() {
   var type = FileSystemEntity.typeSync(platformExeName);
   expectEquals(FileSystemEntityType.NOT_FOUND, type);
 }
 
 void testShouldSucceedWithEmptyPathEnvironment() {
   var command = Platform.isWindows ? 'cmd' : 'ls';
   Process.runSync(command, [],
                   includeParentEnvironment: false,
                   environment: {_SCRIPT_KEY: 'yes', 'PATH': ''});
 }
 
 void testShouldSucceedWithSourcePlatformExecutable() {
-  verify(Platform.executable);
+  verify(Platform.resolvedExecutable);
 }
 
 void testExeSymLinked(Directory dir) {
   var dirUri = new Uri.directory(dir.path);
   var link = new Link.fromUri(dirUri.resolve('dart_exe_link'));
-  link.createSync(Platform.executable);
+  link.createSync(Platform.resolvedExecutable);
   verify(link.path);
 }
 
 void testPathToDirWithExeSymLinked(Directory dir) {
   var dirUri = new Uri.directory(dir.path);
   var link = new Link.fromUri(dirUri.resolve('dart_exe_link'));
-  link.createSync(Platform.executable);
+  link.createSync(Platform.resolvedExecutable);
   verify('dart_exe_link', altPath: dir.path);
 }
 
 /// Create a sym-link to the SDK directory and run 'dart' from that path
 void testExeDirSymLinked(Directory dir) {
   var dirUri = new Uri.directory(dir.path);
 
   var linkDirUri = dirUri.resolve('dart_bin_dir_link');
   var link = new Link.fromUri(linkDirUri);
 
-  var exeFile = new File(Platform.executable);
+  var exeFile = new File(Platform.resolvedExecutable);
 
   link.createSync(exeFile.parent.path);
 
   var linkedBin =
       new Uri.directory(linkDirUri.toFilePath()).resolve(platformExeName);
 
   verify(linkedBin.toFilePath());
 }
 
 void testPathPointsToSymLinkedSDKPath(Directory dir) {
   var dirUri = new Uri.directory(dir.path);
 
   var linkDirUri = dirUri.resolve('dart_bin_dir_link');
   var link = new Link.fromUri(linkDirUri);
 
-  var exeFile = new File(Platform.executable);
+  var exeFile = new File(Platform.resolvedExecutable);
 
   link.createSync(exeFile.parent.path);
 
   verify(platformExeName, altPath: link.path);
 }
 
 void testPathToSDKDir() {
-  var exeFile = new File(Platform.executable);
+  var exeFile = new File(Platform.resolvedExecutable);
   var binDirPath = exeFile.parent.path;
 
   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);
+  var raw = new Uri.file(Platform.resolvedExecutable);
   return raw.pathSegments.last;
 }
 
 String get scriptPath => Platform.script.toFilePath();
 
 void main() {
+  // The same script is used for both running the tests and as for starting
+  // child verifying the value of Platform.resolvedExecutable. If the
+  // environment variable _SCRIPT_KEY is set this is a child process which
+  // should print the value of Platform.resolvedExecutable.
   if (Platform.environment.containsKey(_SCRIPT_KEY)) {
-    print(Platform.executable);
+    print(Platform.resolvedExecutable);
     return;
   }
 
   testDartExecShouldNotBeInCurrentDir();
   testShouldSucceedWithSourcePlatformExecutable(); /// 00: 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
   // dart:io does not support linking to files in Windows.
   if (!Platform.isWindows) {
     withTempDir(testPathToDirWithExeSymLinked); /// 05: ok
   }
   testShouldSucceedWithEmptyPathEnvironment(); /// 06: ok
 }