[kernel] Support for top-level generic functions.

pkg/kernel/testcases/closures/for_in_closure.dart.expect

Index: pkg/kernel/testcases/closures/for_in_closure.dart.expect
diff --git a/pkg/kernel/testcases/closures/for_in_closure.dart.expect b/pkg/kernel/testcases/closures/for_in_closure.dart.expect
index fc7afb1187c5671ccd76fc28aab393d592d8c067..ade4f660b13cb9cb31dfb7f8b87b29dad33c3e91 100644
--- a/pkg/kernel/testcases/closures/for_in_closure.dart.expect
+++ b/pkg/kernel/testcases/closures/for_in_closure.dart.expect
@@ -6,8 +6,8 @@ static const field dynamic numbers = const <core::int>[0, 1, 2, 3, 4, 5, 6, 7, 8
 static method main() → dynamic {
   dynamic closures = <dynamic>[];
   for (core::int i in self::numbers) {
-    final Vector #context = MakeVector(2);
-    #context[1] = i;
+    final Vector #context = MakeVector(3);
+    #context[2] = i;
     {
       closures.add(MakeClosure<() → dynamic>(self::closure#main#function, #context));
     }
@@ -22,5 +22,5 @@ static method main() → dynamic {
   }
 }
 static method closure#main#function(Vector #contextParameter) → dynamic {
-  return #contextParameter[1];
+  return #contextParameter[2];
 }