Implement erasure of local function declarations.

pkg/kernel/lib/ast.dart

 // Copyright (c) 2016, 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.
 
 /// -----------------------------------------------------------------------
 ///                           ERROR HANDLING
 /// -----------------------------------------------------------------------
 ///
 /// As a rule of thumb, errors that can be detected statically are handled by
 /// the frontend, typically by translating the erroneous code into a 'throw' or
@@ skipping 1521 matching lines @@
 
   static NamedType _getNamedTypeOfVariable(VariableDeclaration node) {
     return new NamedType(node.name, node.type);
   }
 
   FunctionType get functionType {
     TreeNode parent = this.parent;
     List<NamedType> named =
         namedParameters.map(_getNamedTypeOfVariable).toList(growable: false);
     named.sort();
+    // We need create a copy of the list of type parameters, otherwise
+    // transformations like erasure don't work.
+    var typeParametersCopy = new List<TypeParameter>.from(parent is Constructor
+        ? parent.enclosingClass.typeParameters
+        : typeParameters);
     return new FunctionType(
         positionalParameters.map(_getTypeOfVariable).toList(growable: false),
         returnType,
         namedParameters: named,
-        typeParameters: parent is Constructor
-            ? parent.enclosingClass.typeParameters
-            : typeParameters,
+        typeParameters: typeParametersCopy,
         requiredParameterCount: requiredParameterCount);
   }
 
   accept(TreeVisitor v) => v.visitFunctionNode(this);
 
   visitChildren(Visitor v) {
     visitList(typeParameters, v);
     visitList(positionalParameters, v);
     visitList(namedParameters, v);
     returnType?.accept(v);
@@ skipping 3187 matching lines @@
   if (typedef_.canonicalName == null) {
     throw '$typedef_ has no canonical name';
   }
   return typedef_.canonicalName;
 }
 
 /// Annotation describing information which is not part of Dart semantics; in
 /// other words, if this information (or any information it refers to) changes,
 /// static analysis and runtime behavior of the library are unaffected.
 const informative = null;