Fix many bugs with closure conversion in checked mode.

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

Index: pkg/kernel/testcases/closures/closure_in_initializer.dart.expect
diff --git a/pkg/kernel/testcases/closures/closure_in_initializer.dart.expect b/pkg/kernel/testcases/closures/closure_in_initializer.dart.expect
index 284c685ad121b9c1ad35eae86ce2f923278d7db1..cb7d03bc48bf2181954f20adbac9d82669bdd5f4 100644
--- a/pkg/kernel/testcases/closures/closure_in_initializer.dart.expect
+++ b/pkg/kernel/testcases/closures/closure_in_initializer.dart.expect
@@ -5,9 +5,9 @@ import "dart:core" as core;
 class C extends core::Object {
   field dynamic t;
   constructor foo(dynamic f, dynamic x) → void
-    : final Vector #context = MakeVector(4), this self::C::foo#redir(f, x, #context)
+    : final dynamic #context = MakeVector(4), this self::C::foo#redir(f, x, #context)
     ;
-  constructor foo#redir(dynamic f, dynamic x, final Vector #context) → void
+  constructor foo#redir(dynamic f, dynamic x, final dynamic #context) → void
     : dynamic #t1 = #context[2] = f, dynamic #t2 = #context[3] = x, self::C::t = MakeClosure<() → dynamic>(self::closure#C#foo#function, #context), super core::Object::•() {
     #context[3] = 1;
     core::print(#context[3]);
@@ -20,9 +20,9 @@ static method main() → dynamic {
   c.t();
   core::print(3);
 }
-static method closure#C#foo#function(Vector #contextParameter) → dynamic {
+static method closure#C#foo#function(dynamic #contextParameter) → dynamic {
   return (#contextParameter[2]).call(#contextParameter[3]);
 }
-static method closure#main#function(Vector #contextParameter, dynamic x) → dynamic {
+static method closure#main#function(dynamic #contextParameter, dynamic x) → dynamic {
   return core::print("hest${x}");
 }