Remove unknown/unused/untested timelocal library function

Found when auditing untested library functions.

This alias function was added back in
48a2a87 as part of the
implemention of time.h function but I can't find anything
about this function existing on any system.

Perhaps it was typo for `localtime`, which is a thing?

Author: sbc100

src/library.js

@@ -580,7 +580,6 @@ LibraryManager.library = {
 
     return (date.getTime() / 1000)|0;
   },
-  timelocal: 'mktime',
 
 #if MINIMAL_RUNTIME
   gmtime_r__deps: ['$allocateUTF8'],