2011-06-06 Ivan Maidanski <ivmai@mail.ru>

2011-06-06  Ivan Maidanski  <ivmai@mail.ru>

	* src/atomic_ops/sysdeps/gcc/arm.h (AO_THUMB_GO_ARM,
	AO_THUMB_RESTORE_MODE, AO_THUMB_SWITCH_CLOBBERS): Define as empty
	for Thumb-2 mode.
	* src/atomic_ops/sysdeps/gcc/arm.h (AO_store, AO_test_and_set,
	AO_fetch_and_add, AO_fetch_and_add1, AO_fetch_and_sub1,
	AO_compare_and_swap, AO_compare_double_and_swap_double): Remove
	unnecessary "memory" keyword from the list of clobbered registers
	(revert part of the previous commit).
	* src/atomic_ops/sysdeps/gcc/arm.h (AO_compare_and_swap): Add
	a comment for "IT" instruction.
	* src/atomic_ops/sysdeps/gcc/arm.h
	(AO_compare_double_and_swap_double): Don't define on the
	architectures where unimplemented; add a comment; replace return
	(in the loop) statement with break.