Add HTM fastpath and use Intel RTM for it on x86.

Add HTM fastpath and use Intel RTM for it on x86.

	* beginend.cc (htm_fastpath): New.
	(gtm_thread::begin_transaction, _ITM_commitTransaction,
	_ITM_commitTransactionEH): Add HTM fastpath handling.
	* config/linux/rwlock.h (gtm_rwlock.is_write_locked): New.
	* config/posix/rwlock.h (gtm_rwlock.is_write_locked): New.
	* config/x86/target.h (htm_available, htm_init, htm_begin_success,
	htm_begin, htm_commit, htm_abort, htm_abort_should_retry): New.
	* configure.tgt: Add -mrtm to XCFLAGS.
	* method-serial.cc (htm_mg, o_htm_mg, htm_dispatch, dispatch_htm): New.
	(gtm_thread::serialirr_mode): Add HTM fastpath handling.
	* libitm_i.h (htm_fastpath, dispatch_htm): Declare.
	* retry.cc (parse_default_method): Add HTM method parsing.
	(gtm_thread::number_of_threads_changed): Use HTM by default if
	available.

From-SVN: r193369