Add type inference support for "call" invocations of function expressions.

pkg/analyzer/test/src/task/strong/front_end_inference_test.dart

 // Copyright (c) 2017, 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.
 
 import 'dart:async';
 import 'dart:convert';
 import 'dart:io';
 
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/ast/visitor.dart';
@@ skipping 294 matching lines @@
         for (int i = 0; i < parameters.length; i++) {
           FormalParameter parameter = parameters[i];
           if (parameter is SimpleFormalParameter && parameter.type == null) {
             _recordType(parameter.offset, type.parameters[i].type);
           }
         }
       }
     }
   }
 
+  @override
+  visitFunctionExpressionInvocation(FunctionExpressionInvocation node) {
+    super.visitFunctionExpressionInvocation(node);
+    if (node.typeArguments == null) {
+      var inferredTypeArguments = _getInferredFunctionTypeArguments(
+              node.function.staticType,
+              node.staticInvokeType,
+              node.typeArguments)
+          .toList();
+      if (inferredTypeArguments.isNotEmpty) {
+        _recordTypeArguments(node.argumentList.offset, inferredTypeArguments);
+      }
+    }
+  }
+
   visitIndexExpression(IndexExpression node) {
     super.visitIndexExpression(node);
     _recordMethodTarget(node.leftBracket.charOffset, node.staticElement);
   }
 
   visitInstanceCreationExpression(InstanceCreationExpression node) {
     super.visitInstanceCreationExpression(node);
     DartType type = node.staticType;
     if (type is InterfaceType) {
       if (type.typeParameters.isNotEmpty &&
@@ skipping 115 matching lines @@
 
   /// Based on DDC code generator's `_recoverTypeArguments`
   Iterable<DartType> _recoverTypeArguments(FunctionType g, FunctionType f) {
     assert(identical(g.element, f.element));
     assert(g.typeFormals.isNotEmpty && f.typeFormals.isEmpty);
     assert(g.typeFormals.length + g.typeArguments.length ==
         f.typeArguments.length);
     return f.typeArguments.skip(g.typeArguments.length);
   }
 }