fix #27040, promote the upper bound of a type parameter

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

Index: pkg/analyzer/test/src/task/strong/checker_test.dart
diff --git a/pkg/analyzer/test/src/task/strong/checker_test.dart b/pkg/analyzer/test/src/task/strong/checker_test.dart
index 9013f2121b5871f8a4c578d7762c3a64a3b1ea90..f5eda5c342327a03d4ed20693ed6f799174dcf6f 100644
--- a/pkg/analyzer/test/src/task/strong/checker_test.dart
+++ b/pkg/analyzer/test/src/task/strong/checker_test.dart
@@ -3699,7 +3699,9 @@ g() {
   }
 
   void test_typePromotionFromTypeParameter() {
-    // Regression test for https://github.com/dart-lang/sdk/issues/26965
+    // Regression test for:
+    // https://github.com/dart-lang/sdk/issues/26965
+    // https://github.com/dart-lang/sdk/issues/27040
     checkFile(r'''
 void f/*<T>*/(/*=T*/ object) {
   if (object is String) print(object.substring(1));
@@ -3714,8 +3716,7 @@ class SubClonable<T> extends Clonable<T> {
 }
 void h/*<T extends Clonable<T>>*/(/*=T*/ object) {

[Leaf, 2016/09/30 05:00:04]

Test that object is usable as a SubClonable<T> as well as a T?

[Jennifer Messerly, 2016/09/30 16:58:03]

I think `object.m` is supposed to illustrate that. Perhaps would be better not
all on the same line though and with comments.

[Leaf, 2016/09/30 17:00:30]

Sort of.  object.m tests that SubClonable methods can be called on it.  Just to
be paranoid I thought it might be useful to check that assignability actually
works as well, since that follows different code paths

   if (/*info:NON_GROUND_TYPE_CHECK_INFO*/object is SubClonable/*<T>*/) {
-    // Note we need to cast back to T, because promotion lost that type info.
-    print(object.m(object as dynamic/*=T*/));
+    print(object.m(object));
   }
 }
 ''');