Revision of "Adjusts dart2js backend to handle method type arguments"

pkg/compiler/lib/src/diagnostics/messages.dart

Index: pkg/compiler/lib/src/diagnostics/messages.dart
diff --git a/pkg/compiler/lib/src/diagnostics/messages.dart b/pkg/compiler/lib/src/diagnostics/messages.dart
index bbe777e09c6d537b8596815b896b5499d80e37ce..830a010ad396a68d44db01c3a90f7fa02f092978 100644
--- a/pkg/compiler/lib/src/diagnostics/messages.dart
+++ b/pkg/compiler/lib/src/diagnostics/messages.dart
@@ -430,6 +430,7 @@ enum MessageKind {
   TYPE_ARGUMENT_COUNT_MISMATCH,
   TYPE_VARIABLE_IN_CONSTANT,
   TYPE_VARIABLE_WITHIN_STATIC_MEMBER,
+  TYPE_VARIABLE_FROM_METHOD_NOT_REIFIED,
   TYPEDEF_FORMAL_WITH_DEFAULT,
   UNARY_OPERATOR_BAD_ARITY,
   UNBOUND_LABEL,
@@ -1152,6 +1153,38 @@ void main() => new C().m(null);
 """
           ]),
 
+      MessageKind.TYPE_VARIABLE_FROM_METHOD_NOT_REIFIED: const MessageTemplate(
+          MessageKind.TYPE_VARIABLE_FROM_METHOD_NOT_REIFIED,
+          "Method type variables are not reified.",
+          howToFix: "Try using the intended upper bound of the "
+              "type variable, or dynamic."
+// TODO(eernst): These examples should be commented in with an `options:`
+// specifying "--generic-method-syntax" and made to work; moreover, the
+// compiler/dart2js test 'generic_method_type_usage' should be transformed to
+// similar examples of the relevant `MessageKind` entries.
+//
+//        examples: const [
+//            """
+// // Method type variables are not reified, so they cannot be returned.
+// Type f<T>() => T;
+//
+// main() => f<int>();
+// """,
+//            """
+// // Method type variables are not reified, so they cannot be tested dynamically.
+// bool f<T>(Object o) => o is T;
+//
+// main() => f<int>(42);
+// """,
+//            """
+// // Method type variables are not reified, so they cannot be tested dynamically.
+// bool f<T>(Object o) => o as T;
+//
+// main() => f<int>(42);
+// """
+//    ]
+      ),
+
       MessageKind.INVALID_TYPE_VARIABLE_BOUND: const MessageTemplate(
           MessageKind.INVALID_TYPE_VARIABLE_BOUND,
           "'#{typeArgument}' is not a subtype of bound '#{bound}' for "