Add weak symbols for __strtol_internal (etc)

Seems certain binaries (such as those compiled on centos) contains inlined
references to __strtol_internal (which in turn seems like a bug to me).

Copied the weak defs from the musl version of the file. Other option
is to modify the musl version to deal with OSv file struct and use that instead.

Refs #339

Signed-off-by: Calle Wilund <calle@cloudius-systems.com>
Signed-off-by: Pekka Enberg <penberg@cloudius-systems.com>

libc/stdlib/strtol.c

@@ -54,3 +54,10 @@ uintmax_t strtoumax(const char *restrict s, char **restrict p, int base)
 {
 	return strtoull(s, p, base);
 }
+
+weak_alias(strtol, __strtol_internal);
+weak_alias(strtoul, __strtoul_internal);
+weak_alias(strtoll, __strtoll_internal);
+weak_alias(strtoull, __strtoull_internal);
+weak_alias(strtoimax, __strtoimax_internal);
+weak_alias(strtoumax, __strtoumax_internal);