match: Don't ever avoid let-binding the matched expression (since

identifiers can have non-trivial effects).  Bug pointed out by RMC.

svn: r3813

collects/mzlib/private/match-internal-func.ss

@@ -15,10 +15,8 @@
   (define-syntax (match stx)
     (syntax-case stx ()
       [(_ exp . clauses)       
-       (if (identifier? #'exp)
-           (gen-match #'exp '() #'clauses stx)
        (with-syntax ([body (gen-match #'x '() #'clauses stx)])
-             #`(let ((x exp)) body)))]))
+         #`(let ([x exp]) body))]))
   
   (define-syntax (match-lambda stx)
     (syntax-case stx ()