POSIX requires that key destructors are called in a loop
for each key with a non-NULL value until all values are
NULL, or until all destructors for non-NULL values
have been called at least PTHREAD_DESTRUCTOR_ITERATIONS
(per POSIX: 4) times.
Cygwinonly called all destructors with non-NULL values
exactly once. This patch fixes Cygwin to follow POSIX.
Signed-off-by: Corinna Vinschen <corinna@vinschen.de>
2a9f6de66e