Reported by Florian Weimer <fweimer@redhat.com>.
Implements an idea by Ondřej Bílka <neleai@seznam.cz>.
* lib/malloca.h (malloca): In the stack allocation case, return a
pointer that is a multiple of 2 * sa_alignment_max.
(sa_increment): Remove enum item.
* lib/xmalloca.h (xmalloca): In the stack allocation case, return
a pointer that is a multiple of 2 * sa_alignment_max.
* lib/malloca.c (NO_SANITIZE_MEMORY): Remove macro.
(MAGIC_NUMBER, MAGIC_SIZE, preliminary_header, HEADER_SIZE, header,
HASH_TABLE_SIZE, mmalloca_results): Remove.
(small_t): New type.
(mmalloca, free): Rewritten.
* lib/malloca.valgrind: Remove file.
* modules/malloca (Files): Remove it.
(Depends-on): Remove verify.