[PATCH 06/16] malloc: Ensure the generic mtag hooks are not used

[DJ Delorie]

Szabolcs Nagy <szabolcs.nagy@arm.com> writes:
> +/* Memory tagging target hooks are only called when memory tagging is
> +   enabled at runtime.  The generic definitions here must not be used.  */
> +void __libc_mtag_link_error (void);

This may make it impossible to compile individual glibc modules with
-O0, say, for debugging purposes.  I do this quite often with malloc.c
and do not want to lose that ability.

Do we trust the compiler's default optimizations (at -O0) to do code
elimination based on constant conditions?