let binding should shadow syntax-parameters

[jcubic]

There is a problem with the current implementation of the syntax-parameters.

(define-syntax foo
  (syntax-rules ()
    ((_ body ...)
     (begin
       (syntax-parameterize
        ((it (syntax-rules ()
               ((_) "hello world"))))
        body ...)))))

(let ((it 10))
  (foo (print it)))

It should print 10.