Implement type inference of constructor invocations in Fasta.

pkg/front_end/testcases/inference/generic_methods_dart_math_min_max.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.
 
 /*@testedFeatures=inference*/
 library test;
 
 import 'dart:math';
 
 void printInt(int x) => print(x);
 void printDouble(double x) => print(x);
 
 num myMax(num x, num y) => max(x, y);
 
-main() {
+f() {
   // Okay if static types match.
   printInt(max(1, 2));
   printInt(min(1, 2));
   printDouble(max(1.0, 2.0));
   printDouble(min(1.0, 2.0));
 
   // No help for user-defined functions from num->num->num.
   printInt(/*info:DOWN_CAST_IMPLICIT*/ myMax(1, 2));
   printInt(myMax(1, 2) as int);
 
   // Mixing int and double means return type is num.
   printInt(max(1, /*error:ARGUMENT_TYPE_NOT_ASSIGNABLE*/ 2.0));
   printInt(min(1, /*error:ARGUMENT_TYPE_NOT_ASSIGNABLE*/ 2.0));
   printDouble(max(/*error:ARGUMENT_TYPE_NOT_ASSIGNABLE*/ 1, 2.0));
   printDouble(min(/*error:ARGUMENT_TYPE_NOT_ASSIGNABLE*/ 1, 2.0));
 
   // Types other than int and double are not accepted.
   printInt(min(
       /*error:ARGUMENT_TYPE_NOT_ASSIGNABLE*/ "hi",
       /*error:ARGUMENT_TYPE_NOT_ASSIGNABLE*/ "there"));
 }
+
+main() {}