Don't compare non-identifiers with free-id=?.

Closes PR 14877.

typed-racket-lib/typed-racket/typecheck/tc-app/tc-app-lambda.rkt

@@ -24,7 +24,7 @@
 (define-tc/app-syntax-class (tc/app-lambda expected)
   #:literal-sets (kernel-literals)
   ;; let loop
-  (pattern ((letrec-values ([(lp) (~and lam (#%plain-lambda (args ...) . body))]) lp*) . actuals)
+  (pattern ((letrec-values ([(lp) (~and lam (#%plain-lambda (args ...) . body))]) lp*:id) . actuals)
     #:when expected
     #:when (not (andmap type-annotation (syntax->list #'(lp args ...))))
     #:when (free-identifier=? #'lp #'lp*)
@@ -59,7 +59,7 @@
   (syntax-parse #`(#,args #,body #,actuals)
     #:literal-sets (kernel-literals lambda-literals)
     [((val acc ...)
-      ((~and inner-body (if (#%plain-app (~or pair? null?) val*) thn els)))
+      ((~and inner-body (if (#%plain-app (~or pair? null?) val*:id) thn els)))
       (actual actuals ...))
      #:when
      (and (free-identifier=? #'val #'val*)

typed-racket-test/tests/typed-racket/unit-tests/typecheck-tests.rkt

@@ -3350,6 +3350,10 @@
                  (ann (values a a) (Values Symbol Symbol)))
                (void))
              -Void]
+
+       [tc-e ((letrec ((loop (lambda: ([x : (Listof Integer)]) (cond ((null? (cdr x)) #t) (else #f))))) loop)
+              (list 1 2))
+             -Boolean]
         )
 
   (test-suite