Add entry-point annotations for test-only code.

testing/dart/plugin_utilities_test.dart

@@ -9,11 +9,15 @@ import 'package:test/test.dart';
 typedef StringFunction = String Function();
 typedef IntFunction = int Function();
 
+@pragma('vm:entry-point', 'get')
 String top() => 'top';
 
+@pragma('vm:entry-point')
 class Foo {
   const Foo();
+  @pragma('vm:entry-point')
   static int getInt() => 1;
+  @pragma('vm:entry-point')
   double getDouble() => 1.0;
 }
 
@@ -23,22 +27,25 @@ void main() {
     final CallbackHandle hTop = PluginUtilities.getCallbackHandle(top)!;
     expect(hTop, isNot(0));
     expect(PluginUtilities.getCallbackHandle(top), hTop);
-    final StringFunction topClosure = PluginUtilities.getCallbackFromHandle(hTop)! as StringFunction;
+    final StringFunction topClosure =
+        PluginUtilities.getCallbackFromHandle(hTop)! as StringFunction;
     expect(topClosure(), 'top');
 
     // Static method callback.
     final CallbackHandle hGetInt = PluginUtilities.getCallbackHandle(Foo.getInt)!;
     expect(hGetInt, isNot(0));
     expect(PluginUtilities.getCallbackHandle(Foo.getInt), hGetInt);
-    final IntFunction getIntClosure = PluginUtilities.getCallbackFromHandle(hGetInt)! as IntFunction;
+    final IntFunction getIntClosure =
+        PluginUtilities.getCallbackFromHandle(hGetInt)! as IntFunction;
     expect(getIntClosure(), 1);
 
     // Instance method callbacks cannot be looked up.
     const Foo foo = Foo();
     expect(PluginUtilities.getCallbackHandle(foo.getDouble), isNull);
 
     // Anonymous closures cannot be looked up.
-    final Function anon = (int a, int b) => a + b; // ignore: prefer_function_declarations_over_variables
+    final Function anon = // ignore: prefer_function_declarations_over_variables
+        (int a, int b) => a + b;
     expect(PluginUtilities.getCallbackHandle(anon), isNull);
   });
 }

testing/dart/spawn_helper.dart

@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+@pragma('vm:entry-point', 'get')
 void main() {}
 
 @pragma('vm:entry-point')