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