Issue 29360. Fix type name resolution for GenericTypeAliasElement.

pkg/analyzer/lib/src/generated/resolver.dart

 // Copyright (c) 2014, 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.
 
 library analyzer.src.generated.resolver;
 
 import 'dart:collection';
 
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/ast/standard_resolution_map.dart';
@@ skipping 8401 matching lines @@
         for (int i = 0; i < parameterCount; i++) {
           typeArguments[i] = _getType(arguments[i]);
         }
       } else {
         reportErrorForNode(_getInvalidTypeParametersErrorCode(node), node,
             [typeName.name, parameterCount, argumentCount]);
         for (int i = 0; i < parameterCount; i++) {
           typeArguments[i] = dynamicType;
         }
       }
-      type = typeSystem.instantiateType(type, typeArguments);
+      if (element is GenericTypeAliasElementImpl) {
+        type = element.typeAfterSubstitution(typeArguments) ?? dynamicType;
+      } else {
+        type = typeSystem.instantiateType(type, typeArguments);
+      }
     } else {
-      type = typeSystem.instantiateToBounds(type);
+      if (element is GenericTypeAliasElementImpl) {
+        type = element.typeAfterSubstitution(null) ?? dynamicType;
+      } else {
+        type = typeSystem.instantiateToBounds(type);
+      }
     }
     typeName.staticType = type;
     node.type = type;
   }
 
   /**
    * The number of type arguments in the given [typeName] does not match the
    * number of parameters in the corresponding class element. Return the error
    * code that should be used to report this error.
    */
@@ skipping 44 matching lines @@
         TypeArgumentList argumentList = annotation.typeArguments;
         List<DartType> typeArguments = null;
         if (argumentList != null) {
           List<TypeAnnotation> arguments = argumentList.arguments;
           int argumentCount = arguments.length;
           typeArguments = new List<DartType>(argumentCount);
           for (int i = 0; i < argumentCount; i++) {
             typeArguments[i] = _getType(arguments[i]);
           }
         }
-        return element.typeAfterSubstitution(typeArguments);
+        return element.typeAfterSubstitution(typeArguments) ?? dynamicType;
       }
     }
     return type;
   }
 
   /**
    * Returns the simple identifier of the given (may be qualified) type name.
    *
    * @param typeName the (may be qualified) qualified type name
    * @return the simple identifier of the given (may be qualified) type name.
@@ skipping 2423 matching lines @@
       return null;
     }
     if (identical(node.staticElement, variable)) {
       if (node.inSetterContext()) {
         result = true;
       }
     }
     return null;
   }
 }