Reapply "reflectType() dynamic type arguments support (#26012)"

runtime/lib/mirrors_impl.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.
 
 // VM-specific implementation of the dart:mirrors library.
 
 var _dirty = false;
 final _emptyList = new UnmodifiableListView([]);
 
 class _InternalMirrorError {
@@ skipping 1627 matching lines @@
   static InstanceMirror reflect(Object reflectee) {
     return reflectee is Function
         ? new _LocalClosureMirror(reflectee)
         : new _LocalInstanceMirror(reflectee);
   }
 
   static ClassMirror makeLocalClassMirror(Type key)
       native "Mirrors_makeLocalClassMirror";
   static TypeMirror makeLocalTypeMirror(Type key)
       native "Mirrors_makeLocalTypeMirror";
+  static Type instantiateGenericType(Type key, typeArguments)
+      native "Mirrors_instantiateGenericType";
 
   static Expando<ClassMirror> _declarationCache = new Expando("ClassMirror");
   static Expando<TypeMirror> _instantiationCache = new Expando("TypeMirror");
 
   static ClassMirror reflectClass(Type key) {
     var classMirror = _declarationCache[key];
     if (classMirror == null) {
       classMirror = makeLocalClassMirror(key);
       _declarationCache[key] = classMirror;
       if (!classMirror._isGeneric) {
         _instantiationCache[key] = classMirror;
       }
     }
     return classMirror;
   }
 
-  static TypeMirror reflectType(Type key) {
+  static TypeMirror reflectType(Type key, [List<Type> typeArguments]) {
+    if (typeArguments != null) {
+      key = _instantiateType(key, typeArguments);
+    }
     var typeMirror = _instantiationCache[key];
     if (typeMirror == null) {
       typeMirror = makeLocalTypeMirror(key);
       _instantiationCache[key] = typeMirror;
       if (typeMirror is ClassMirror && !typeMirror._isGeneric) {
         _declarationCache[key] = typeMirror;
       }
     }
     return typeMirror;
   }
+
+  static Type _instantiateType(Type key, List<Type> typeArguments) {
+    if (typeArguments.isEmpty) {
+      throw new ArgumentError.value(
+        typeArguments, 'typeArguments', 'Type arguments list cannot be empty.');
+    }
+    return instantiateGenericType(key, typeArguments.toList(growable: false));
+  }
 }