Add "_" separator for new labels created for functions

interp.rkt

@@ -1157,7 +1157,7 @@
            (match f-val
              [(CFunction xs info blocks def-env)
               (define f (dict-ref info 'name))
-              (define f-start (symbol-append f 'start))
+              (define f-start (symbol-append f '_start))
               (define new-env (append (map cons xs arg-vals) def-env))
               (parameterize ([get-basic-blocks blocks])
                 ((interp-C-tail new-env) (dict-ref blocks f-start)))]
@@ -1178,7 +1178,7 @@
            (match f-val
              [(CFunction xs info blocks def-env)
               (define f (dict-ref info 'name))
-              (define f-start (symbol-append f 'start))
+              (define f-start (symbol-append f '_start))
               (define new-env (append (map cons xs arg-vals) def-env))
               (parameterize ([get-basic-blocks blocks])
                 ((interp-C-tail new-env) (dict-ref blocks f-start)))]
@@ -1260,7 +1260,7 @@
          (define result-env
            (parameterize ([get-basic-blocks blocks])
              ((interp-x86-block new-env)
-              (dict-ref blocks (symbol-append f 'start)))))
+              (dict-ref blocks (symbol-append f '_start)))))
          (set! root-stack-pointer (- root-stack-pointer root-size))
          (define res (lookup 'rax result-env))
          ;; return and continue after the function call, back in env

type-check-Cfun.rkt

@@ -50,7 +50,7 @@
            (define new-env (append (map cons xs ps) global-env))
            (define env^ (make-hash new-env))
            (define-values (env t)
-             (type-check-blocks info blocks env^ (symbol-append f 'start)))
+             (type-check-blocks info blocks env^ (symbol-append f '_start)))
            (unless (type-equal? t rt)
              (error 'type-check "mismatch in return type, ~a != ~a" t rt))
            (define locals-types