syntax-parametereize: fix set! with rename transformers

Relevant to bootstrapworld/curr#423

pkgs/racket-test-core/tests/racket/stxparam.rktl

@@ -168,6 +168,18 @@
       (define trois (slv num))))
   (test #t = trois 3))
 
+(let ()
+  (define x 1)
+  (define y 10)
+  (define-rename-transformer-parameter num
+    (make-rename-transformer #'y))
+  (syntax-parameterize ([num (make-rename-transformer #'x)])
+    (test #t = num 1)
+    (set! num 3)
+    (test #t = num 3))
+  (test #t = x 3)
+  (test #t = num 10))
+
 ;; ----------------------------------------
 
 (let ()

racket/collects/racket/private/stxparamkey.rkt

@@ -2,7 +2,8 @@
 (module stxparamkey '#%kernel
   (#%require "small-scheme.rkt" "define.rkt" 
              "stxcase.rkt" "stxloc.rkt" "with-stx.rkt"
-             (only '#%unsafe unsafe-root-continuation-prompt-tag))
+             (only '#%unsafe unsafe-root-continuation-prompt-tag)
+             (for-template '#%kernel))
   
   ;; Consulted before the expander's table, for use by compile-time
   ;; code wrapped by a run-time-phased `syntax-parameterize`: