Resolve the executable path on Mac OS when sym-linked

tests/standalone/io/platform_executable_test.dart

Index: tests/standalone/io/platform_executable_test.dart
diff --git a/tests/standalone/io/platform_executable_test.dart b/tests/standalone/io/platform_executable_test.dart
index 638be57d512c9cf2ad1c4235e9ef49db4ed236fc..a81cc2751a149dbc8a9bb731a8a9e3b342f0360e 100644
--- a/tests/standalone/io/platform_executable_test.dart
+++ b/tests/standalone/io/platform_executable_test.dart
@@ -135,10 +135,16 @@ void main() {
 
   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
 }