Add support for converted closures with explicit contexts to VM

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

 library;
 import self as self;
 import "dart:core" as core;
 
 static method f_1_1_no_default(dynamic a, [dynamic b = null]) → dynamic {
   return a.+(b);
 }
 static method f_1_1_default(dynamic a, [dynamic b = 2]) → dynamic {
   return a.+(b);
 }
@@ skipping 31 matching lines @@
       throw "Unexpected result: ${result}.";
   }
   else {
     if(!threw)
       throw "Expected exception missing.";
     if(!0.==(result))
       throw "Unexpected result: ${result}.";
   }
 }
 static method main(dynamic arguments) → dynamic {
-  self::test_1_1(MakeClosure<(dynamic, [dynamic]) → dynamic>(self::closure#f_1_1_no_default, null), false);
-  self::test_1_1(MakeClosure<(dynamic, [dynamic]) → dynamic>(self::closure#f_1_1_default, null), true);
-  self::test_1_b(MakeClosure<(dynamic, {b: dynamic}) → dynamic>(self::closure#f_1_b_no_default, null), false);
-  self::test_1_b(MakeClosure<(dynamic, {b: dynamic}) → dynamic>(self::closure#f_1_b_default, null), true);
+  self::test_1_1(self::f_1_1_no_default, false);
+  self::test_1_1(self::f_1_1_default, true);
+  self::test_1_b(self::f_1_b_no_default, false);
+  self::test_1_b(self::f_1_b_default, true);
 }
-static method closure#f_1_1_no_default(Vector #contextParameter, dynamic a, [dynamic b = null]) → dynamic
-  return self::f_1_1_no_default(a, b);
-static method closure#f_1_1_default(Vector #contextParameter, dynamic a, [dynamic b = 2]) → dynamic
-  return self::f_1_1_default(a, b);
-static method closure#f_1_b_no_default(Vector #contextParameter, dynamic a, {dynamic b = null}) → dynamic
-  return self::f_1_b_no_default(a, b: b);
-static method closure#f_1_b_default(Vector #contextParameter, dynamic a, {dynamic b = 2}) → dynamic
-  return self::f_1_b_default(a, b: b);