Based on these comments in malloc.c:
size field is or'ed with NON_MAIN_ARENA if the chunk was obtained
from a non-main arena. This is only set immediately before handing
the chunk to the user, if necessary.
The NON_MAIN_ARENA flag is never set for unsorted chunks, so it
does not have to be taken into account in size comparisons.
When we pull a chunk off the unsorted list (or any list) we need to
make sure that flag is set properly before returning the chunk.
Use the rounded-up size for chunk_ok_for_memalign()
Do not scan the arena for reusable chunks if there's no arena.
Account for chunk overhead when determining if a chunk is a reuse
candidate.
mcheck interferes with memalign, so skip mcheck variants of
memalign tests.
Reviewed-by: Carlos O'Donell <carlos@redhat.com>
Tested-by: Carlos O'Donell <carlos@redhat.com>