stdlib: atexit: include <sys/cdefs.h>

Change-Id: Ib9eb167710a021e0a2b5c77a06a9338cdc748e6d
Update linker README.

Change-Id: Icaa353e9cf1848c86e7445f4ad590bdab44f7941
Merge "Update linker README."
Fix pthreads functions that should return ESRCH.

imgtec pointed out that pthread_kill(3) was broken, but most of the
other functions that ought to return ESRCH for invalid/exited threads
were equally broken.

Change-Id: I96347f6195549aee0c72dc39063e6c5d06d2e01f
Merge "Fix pthreads functions that should return ESRCH."
Merge "stdlib: atexit: include <sys/cdefs.h>"
use architecture-specific ssize_t definition

after change 32822 was rejected, this is the more light-weight
version of the fix: libc/include/sys/types.h already - via
libc/kernel/common/linux/posix_types.h - includes a definition
of __kernel_ssize_t from libc/kernel/arch-*/asm/posix_types.h
which is architecture-specific, toolchain-agnostic and also
gets rid of the gcc -Wformat warning (which it issues correctly,
since this i̲s̲ indeed a bug in bionic)

Change-Id: Ie4503ab16628bc25815a836d07556f665e9795c7
Merge "use architecture-specific ssize_t definition"
Provide android_filesystem_config, which depends Android style fs