drd: Avoid that the drd/tests/pth_mutex_reinit test fails with glibc >= 2.18

Apparently with glibc >= 2.18 the value returned by pthread_mutexattr_gettype()
is not the same as the value passed to pthread_mutexattr_settype(). Add a
workaround for this glibc bug.


git-svn-id: svn://svn.valgrind.org/valgrind/trunk@13792 a5019735-40e9-0310-863c-91ae7b9d1cf9
drd/tests/trylock: Make this test pass for glibc >= 2.18

git-svn-id: svn://svn.valgrind.org/valgrind/trunk@13793 a5019735-40e9-0310-863c-91ae7b9d1cf9