Fix many bugs with closure conversion in checked mode.

pkg/kernel/testcases/closures/loop2.dart.expect

Index: pkg/kernel/testcases/closures/loop2.dart.expect
diff --git a/pkg/kernel/testcases/closures/loop2.dart.expect b/pkg/kernel/testcases/closures/loop2.dart.expect
index 13fbab74c35c7b8673b1e3fc6974ec3fed5cf4ff..616cf0797f8192102aab58cd30857854a44f0cf2 100644
--- a/pkg/kernel/testcases/closures/loop2.dart.expect
+++ b/pkg/kernel/testcases/closures/loop2.dart.expect
@@ -3,14 +3,14 @@ import self as self;
 import "dart:core" as core;
 
 static method doit(core::int x) → void {
-  final Vector #context = MakeVector(3);
+  final dynamic #context = MakeVector(3);
   #context[2] = x;
   final core::int max = 10;
   final core::double expectedSum = max.-(1).*(max)./(2);
   core::int counter = 0;
   dynamic calls = <dynamic>[];
   while (counter.<(max)) {
-    final Vector #context = MakeVector(3);
+    final dynamic #context = MakeVector(3);
     #context[1] = #context;
     #context[2] = counter;
     calls.add(MakeClosure<() → dynamic>(self::closure#doit#function, #context));
@@ -25,6 +25,6 @@ static method doit(core::int x) → void {
 static method main() → void {
   self::doit(0);
 }
-static method closure#doit#function(Vector #contextParameter) → dynamic {
+static method closure#doit#function(dynamic #contextParameter) → dynamic {
   return (#contextParameter[2]).+(#contextParameter[1][2]);
 }