Fix kernel-struct tests in TR.

collects/tests/typed-scheme/unit-tests/typecheck-tests.rkt

@@ -1356,8 +1356,6 @@
         |#
 
         ;Kernel Structs, check that their hidden identifiers type
-        ;Currently broken in test-suite because of binding differences
-        #;
         (tc-e (void exn
                     exn:fail
                     exn:fail:contract

collects/typed-scheme/base-env/base-structs.rkt

@@ -7,7 +7,9 @@
  (except-in (rep filter-rep object-rep type-rep) make-arr)
  (types convenience union)
  (only-in (types convenience) [make-arr* make-arr])
- (typecheck tc-structs))
+ (typecheck tc-structs)
+ ;;For tests
+ (prefix-in k: '#%kernel))
 
 (require (for-template racket/base (prefix-in k: '#%kernel)))