add suppression for helgrind/tests/tc22_exit_w_lock

add suppression for helgrind/tests/tc22_exit_w_lock

Function pthread_create indirectly calls function memcpy. Helgrind
considers that memcpy is not thread safe function. For error reported
from pthread_create there is the suppression helgrind---_dl_allocate_tls
in the file glibc-2.34567-NPTL-helgrind.supp.
Since glibc version 2.23, memcpy is implemented by __mempcpy_inline.
This causes that call to memcpy from pthread_create is no longer
recognized by the suppression.
In test helgrind/tests/tc22_exit_w_lock, pthread_create is called twice,
and second call reports error, which causes failing of the test.
This patch adds suppression for glibc 2.23 and greater.

Patch by Tamara Vlahovic.

Related issue #375806.

git-svn-id: svn://svn.valgrind.org/valgrind/trunk@16219