instantiate generic tear-offs, fixes #525

test/codegen/language/generic_tearoff_test.dart

+// Copyright (c) 2016, 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:math' as math;
+import 'dart:math' show min; // <-- generic: <T extends num>(T, T) -> T
+import 'package:expect/expect.dart';
+
+class C {
+  /*=T*/ m/*<T extends num>*/(/*=T*/ x, /*=T*/ y) => min(x, y);
+  int m2(int x, int y) => min(x, y);
+}
+
+typedef int Int2Int2Int(int x, int y);
+
+void _test(Int2Int2Int f) {
+  int y = f(123, 456);
+  Expect.equals(y, 123);
+  // `f` doesn't take type args.
+  Expect.throws(() => (f as dynamic)/*<int>*/(123, 456)); 
+}
+
+void _testParam(/*=T*/ minFn/*<T extends num>*/(/*=T*/ x, /*=T*/ y)) {
+  _test(minFn);
+}
+
+main() {
+  // Strong mode infers: `min<int>`
+  // Test simple/prefixed identifiers and property access
+  _test(min); 
+  _test(math.min);
+  _test(new C().m);
+
+  // Test local function, variable, and parameter
+  /*=T*/ m/*<T extends num>*/(/*=T*/ x, /*=T*/ y) => min(x, y);
+  _test(m);
+  final f = min;
+  _test(f);
+  _testParam(math.min);
+
+  // A few misc tests for methods
+  Expect.equals(123, (new C() as dynamic).m/*<int>*/(123, 456));
+  Expect.throws(() => (new C() as dynamic).m2/*<int>*/(123, 456));
+}