linux-atomic.c (__kernel_cmpxchg2): New.

linux-atomic.c (__kernel_cmpxchg2): New.

	* config/pa/linux-atomic.c (__kernel_cmpxchg2): New.
	(FETCH_AND_OP_2): New.  Use for subword and double word operations.
	(OP_AND_FETCH_2): Likewise.
	(COMPARE_AND_SWAP_2): Likewise.
	(SYNC_LOCK_TEST_AND_SET_2): Likewise.
	(SYNC_LOCK_RELEASE_2): Likewise.
	(SUBWORD_SYNC_OP): Remove.
	(SUBWORD_VAL_CAS): Likewise.
	(SUBWORD_BOOL_CAS): Likewise.
	(FETCH_AND_OP_WORD): Update.
	Consistently use signed types.

Co-Authored-By: John David Anglin <danglin@gcc.gnu.org>
From-SVN: r217956