Generated front_end/testcases/inference test files from Analyzer tests.

pkg/front_end/testcases/inference/infer_prefix_expression_custom.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;
+
+class A {
+  A();
+  int operator ~() => 1;
+  double operator -() => 2.0;
+}
+
+var /*@topType=A*/ a = new A();
+var /*@topType=int*/ v_complement = ~a;
+var /*@topType=double*/ v_negate = -a;