Fuchsia: resolve executable name, fetch environment vars

runtime/tests/vm/dart/hello_fuchsia_test.dart

Index: runtime/tests/vm/dart/hello_fuchsia_test.dart
diff --git a/runtime/tests/vm/dart/hello_fuchsia_test.dart b/runtime/tests/vm/dart/hello_fuchsia_test.dart
index bcda2bfab336050b20e3c2ecf5a6ccfaad3dd7e0..ce9cd7da7fe07ea3b22ca17885b71472a80364d1 100644
--- a/runtime/tests/vm/dart/hello_fuchsia_test.dart
+++ b/runtime/tests/vm/dart/hello_fuchsia_test.dart
@@ -380,10 +380,12 @@ Future testGoogleHttps(SecurityContext context, String outcome) async {
 }
 
 Future testProcess() async {
-  Process p = await Process.start(Platform.executable, ["--version"]);
+  String exe = Platform.resolvedExecutable;
+  print("Running $exe --version");
+  Process p = await Process.start(exe, ["--version"]);
   p.stderr.transform(UTF8.decoder).listen(print);
   int code = await p.exitCode;
-  print("dart --version exited with code $code");
+  print("$exe --version exited with code $code");
 }
 
 Future testLs(String path) async {
@@ -393,6 +395,14 @@ Future testLs(String path) async {
   }
 }
 
+void testPlatformEnvironment() {
+  Map<String, String> env = Platform.environment;
+  for (String k in env.keys) {
+    String v = env[k];
+    print("$k = '$v'");
+  }
+}
+
 main() async {
   print("Hello, Fuchsia!");
 
@@ -428,6 +438,10 @@ main() async {
   await testLs("/");
   print("lsTest done");
 
+  print("testPlatformEnvironment");
+  testPlatformEnvironment();
+  print("testPlatformEnvironment done");
+
   print("testProcess");
   await testProcess();
   print("testProcess done");