Delete orphaned comment (#29917)

(The function this described was deleted by PR #23743, the comment was accidentally retained.)

Author: gvanrossum

Python/compile.c

@@ -5064,11 +5064,6 @@ compiler_visit_keyword(struct compiler *c, keyword_ty k)
     return 1;
 }
 
-/* Test whether expression is constant.  For constants, report
-   whether they are true or false.
-
-   Return values: 1 for true, 0 for false, -1 for non-constant.
- */
 
 static int
 compiler_with_except_finish(struct compiler *c, basicblock * cleanup) {