Fix typos in arm_v6.h, ia64.h, acquire_release_volatile.template

Fix typos in arm_v6.h, ia64.h, acquire_release_volatile.template

* src/atomic_ops/sysdeps/armcc/arm_v6.h [!AO_UNIPROCESSOR]
(AO_nop_full): Fix typo ("a data memory barrier") in comment.
* src/atomic_ops/sysdeps/icc/ia64.h (AO_char_load_acquire): Fix typo
("a ld.acq instruction") in comment.
* src/atomic_ops/sysdeps/loadstore/acquire_release_volatile.template
(AO_XSIZE_load_acquire): Likewise.
* src/atomic_ops/sysdeps/icc/ia64.h (AO_short_load_acquire,
AO_int_load_acquire): Remove comment duplicating that in
AO_char_load_acquire.
* src/atomic_ops/sysdeps/loadstore/acquire_release_volatile.template
(AO_XSIZE_store_release): Fix typo ("a st.rel instruction") in comment.
* src/atomic_ops/sysdeps/loadstore/acquire_release_volatile.h:
Regenerate.
* src/atomic_ops/sysdeps/loadstore/char_acquire_release_volatile.h:
Likewise.
* src/atomic_ops/sysdeps/loadstore/int_acquire_release_volatile.h:
Likewise.
* src/atomic_ops/sysdeps/loadstore/short_acquire_release_volatile.h:
Likewise.