Fix several bugs in closure conversion.

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 ade4f660b13cb9cb31dfb7f8b87b29dad33c3e91..8f9883881b5834aea99fc970af61c657e8bcdd95 100644
--- a/pkg/kernel/testcases/closures/for_in_closure.dart.expect
+++ b/pkg/kernel/testcases/closures/for_in_closure.dart.expect
@@ -5,8 +5,11 @@ 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);
+  #context[2] = 0;
   for (core::int i in self::numbers) {
     final Vector #context = MakeVector(3);
+    #context[1] = #context;
     #context[2] = i;
     {
       closures.add(MakeClosure<() → dynamic>(self::closure#main#function, #context));
@@ -22,5 +25,5 @@ static method main() → dynamic {
   }
 }
 static method closure#main#function(Vector #contextParameter) → dynamic {
-  return #contextParameter[2];
+  return (#contextParameter[2]).+(#contextParameter[1][2]);
 }