re PR other/53889 (Gthreads doesn't support destroying recursive mutexes)

libgcc:

	PR other/53889
	* gthr.h (__gthread_recursive_mutex_destroy): Document new required
	function.
	* gthr-posix.h (__gthread_recursive_mutex_destroy): Define.
	* gthr-single.h (__gthread_recursive_mutex_destroy): Likewise.
	* config/gthr-rtems.h (__gthread_recursive_mutex_destroy): Likewise.
	* config/gthr-vxworks.h (__gthread_recursive_mutex_destroy): Likewise.
	* config/i386/gthr-win32.h (__gthread_recursive_mutex_destroy):
	Likewise.
	* config/mips/gthr-mipssde.h (__gthread_recursive_mutex_destroy):
	Likewise.
	* config/pa/gthr-dce.h (__gthread_recursive_mutex_destroy): Likewise.
	* config/s390/gthr-tpf.h (__gthread_recursive_mutex_destroy): Likewise.

libstdc++-v3:

	PR other/53889
	* include/std/mutex (__recursive_mutex_base::~__recursive_mutex_base):
	Use __gthread_recursive_mutex_destroy.
	(__recursive_mutex_base::_S_destroy): Remove.
	(__recursive_mutex_base::_S_destroy_win32): Likewise.
	* include/ext/concurrence.h (__recursive_mutex::~__recursive_mutex):
	Use __gthread_recursive_mutex_destroy.
	(__recursive_mutex::_S_destroy): Remove.
	(__recursive_mutex::_S_destroy_win32): Likewise.

From-SVN: r192002