Fix two issues related to thread private data in asr.
- setting up asr in single thread mode and then starting threads using asr
would lead to multiple threads sharing the same resolver.
- destruction of a thread that has been using asr would leak data.
Problem originally reported by Alexey Sokolov and Uli Schlachter.
ok kettenis@

Make the "not my pool" searching loop a tiny bit smarter, while
making the number of pools variable. Do not document the malloc
conf settings atm, don't know yet if they will stay. Thanks to all
the testers. ok deraadt@

Move mutex, condvar, and thread-specific data routes, pthread_once, and
pthread_exit from libpthread to libc, along with low-level bits to
support them. Major bump to both libc and libpthread.

Requested by libressl team. Ports testing by naddy@
ok kettenis@

Copy files from ../librthread in preparation for moving functionality
from libpthread to libc. No changes to the build yet, just making it
easier to review the substantive diffs.

ok beck@ kettenis@ tedu@

Make the "not my pool" searching loop a tiny bit smarter, while
making the number of pools variable. Do not document the malloc
conf settings atm, don't know yet if they will stay. Thanks to all
the testers. ok deraadt@

Move mutex, condvar, and thread-specific data routes, pthread_once, and
pthread_exit from libpthread to libc, along with low-level bits to
support them. Major bump to both libc and libpthread.

Requested by libressl team. Ports testing by naddy@
ok kettenis@

Copy files from ../librthread in preparation for moving functionality
from libpthread to libc. No changes to the build yet, just making it
easier to review the substantive diffs.

ok beck@ kettenis@ tedu@

Move mutex, condvar, and thread-specific data routes, pthread_once, and
pthread_exit from libpthread to libc, along with low-level bits to
support them. Major bump to both libc and libpthread.

Requested by libressl team. Ports testing by naddy@
ok kettenis@

Copy files from ../librthread in preparation for moving functionality
from libpthread to libc. No changes to the build yet, just making it
easier to review the substantive diffs.

ok beck@ kettenis@ tedu@