Fix many bugs with closure conversion in checked mode.

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 8f9883881b5834aea99fc970af61c657e8bcdd95..e3180e415ca4a15cd93a1f2455f7d962c5a94901 100644
--- a/pkg/kernel/testcases/closures/for_in_closure.dart.expect
+++ b/pkg/kernel/testcases/closures/for_in_closure.dart.expect
@@ -5,10 +5,10 @@ import "dart:core" as core;
 static const field dynamic numbers = const <core::int>[0, 1, 2, 3, 4, 5, 6, 7, 8, 9];
 static method main() → dynamic {
   dynamic closures = <dynamic>[];
-  final Vector #context = MakeVector(3);
+  final dynamic #context = MakeVector(3);
   #context[2] = 0;
   for (core::int i in self::numbers) {
-    final Vector #context = MakeVector(3);
+    final dynamic #context = MakeVector(3);
     #context[1] = #context;
     #context[2] = i;
     {
@@ -24,6 +24,6 @@ static method main() → dynamic {
     throw core::Exception::•("Unexpected sum = ${sum} != ${expectedSum}");
   }
 }
-static method closure#main#function(Vector #contextParameter) → dynamic {
+static method closure#main#function(dynamic #contextParameter) → dynamic {
   return (#contextParameter[2]).+(#contextParameter[1][2]);
 }