Fuse top level type inference with dependency generation.

pkg/front_end/testcases/inference_new/strongly_connected_component.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;
+
+bool f() => null;
+
+// Even though x, y, and z form a strongly connected component (each depends on
+// all the others), the circularity is calculated based on the first problematic
+// dependency of each field.  So x's first problematic dependency is y, and y's
+// first problematic dependency is x; therefore x and y are considered to have a
+// circularity, and for error recovery their type is set to `dynamic`.
+// Thereafter, z infers without problems.
+
+var /*@topType=dynamic*/ x = /*@returnType=dynamic*/ () => f() ? y : z;
+var /*@topType=dynamic*/ y = /*@returnType=dynamic*/ () => x;
+var /*@topType=() -> dynamic*/ z = /*@returnType=dynamic*/ () => x;
+
+main() {}