Fix template-based headers regeneration order in src/Makefile

* src/Makefile.am (BUILT_SOURCES): Define to force regeneration
of generalize-arithm.h, generalize-small.h (if the corresponding
source template is changed) before compilation of .c files (that use
atomic_ops.h).
Group all X_acquire_release_volatile.h and X_[aligned_]atomic_load_store.h
in separate folder

* src/Makefile.am (nobase_private_HEADERS): Update path to
acquire_release_volatile.h, aligned_atomic_load_store.h,
atomic_load_store.h, char_acquire_release_volatile.h,
char_atomic_load_store.h, int_acquire_release_volatile.h,
int_aligned_atomic_load_store.h, int_atomic_load_store.h,
short_acquire_release_volatile.h, short_aligned_atomic_load_store.h,
short_atomic_load_store.h entries (add "loadstore" to prefix).
* src/atomic_ops/sysdeps/all_acquire_release_volatile.h: Likewise.
* src/atomic_ops/sysdeps/all_aligned_atomic_load_store.h: Likewise.
* src/atomic_ops/sysdeps/all_atomic_load_store.h: Likewise.
* src/atomic_ops/sysdeps/gcc/alpha.h: Likewise.
* src/atomic_ops/sysdeps/gcc/mips.h: Likewise.
* src/atomic_ops/sysdeps/hpc/hppa.h: Likewise.
* src/atomic_ops/sysdeps/acquire_release_volatile.h: Move file to
src/atomic_ops/sysdeps/loadstore folder.
* src/atomic_ops/sysdeps/loadstore/aligned_atomic_load_store.h:
Likewise.
* src/atomic_ops/sysdeps/loadstore/atomic_load_store.h: Likewise.
* src/atomic_ops/sysdeps/loadstore/char_acquire_release_volatile.h:
Likewise.
* src/atomic_ops/sysdeps/loadstore/char_atomic_load_store.h: Likewise.
* src/atomic_ops/sysdeps/loadstore/int_acquire_release_volatile.h:
Likewise.
* src/atomic_ops/sysdeps/loadstore/int_aligned_atomic_load_store.h:
Likewise.
* src/atomic_ops/sysdeps/loadstore/int_atomic_load_store.h: Likewise.
* src/atomic_ops/sysdeps/loadstore/short_acquire_release_volatile.h:
Likewise.
* src/atomic_ops/sysdeps/loadstore/short_aligned_atomic_load_store.h:
Likewise.
* src/atomic_ops/sysdeps/loadstore/short_atomic_load_store.h:
Likewise.
* src/atomic_ops/sysdeps/all_acquire_release_volatile.h: Reformat
comment.
* src/atomic_ops/sysdeps/all_aligned_atomic_load_store.h: Likewise.
* src/atomic_ops/sysdeps/all_atomic_load_store.h: Likewise.
Generate 'loadstore' headers from templates

* src/Makefile.am (EXTRA_DIST): Add acquire_release_volatile.template,
aligned_atomic_load_store.template, atomic_load_store.template
entires.
* src/Makefile.am (BUILT_SOURCES): Add acquire_release_volatile.h,
aligned_atomic_load_store.h, atomic_load_store.h,
char_acquire_release_volatile.h, char_atomic_load_store.h,
int_acquire_release_volatile.h, int_aligned_atomic_load_store.h,
int_atomic_load_store.h, short_acquire_release_volatile.h,
short_aligned_atomic_load_store.h, short_atomic_load_store.h entires.
* src/Makefile.am
(atomic_ops/sysdeps/loadstore/acquire_release_volatile.h,
atomic_ops/sysdeps/loadstore/char_acquire_release_volatile.h,
atomic_ops/sysdeps/loadstore/int_acquire_release_volatile.h,
atomic_ops/sysdeps/loadstore/short_acquire_release_volatile.h,
atomic_ops/sysdeps/loadstore/aligned_atomic_load_store.h,
atomic_ops/sysdeps/loadstore/int_aligned_atomic_load_store.h,
atomic_ops/sysdeps/loadstore/short_aligned_atomic_load_store.h,
atomic_ops/sysdeps/loadstore/atomic_load_store.h,
atomic_ops/sysdeps/loadstore/char_atomic_load_store.h,
atomic_ops/sysdeps/loadstore/int_atomic_load_store.h,
atomic_ops/sysdeps/loadstore/short_atomic_load_store.h): New rules (to
generate header from the corresponding template).
* src/atomic_ops/sysdeps/loadstore/acquire_release_volatile.template:
New template header (code copied from the corresponding header of
"loadstore" folder and parameterized with XSIZE and XCTYPE); update
header comment.
* src/atomic_ops/sysdeps/loadstore/aligned_atomic_load_store.template:
Likewise.
* src/atomic_ops/sysdeps/loadstore/atomic_load_store.template:
Likewise.
* src/atomic_ops/sysdeps/loadstore/acquire_release_volatile.template
(AO_GCC_BARRIER): Add TODO item.
* 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.
* src/atomic_ops/sysdeps/loadstore/aligned_atomic_load_store.h:
Likewise.
* src/atomic_ops/sysdeps/loadstore/int_aligned_atomic_load_store.h:
Likewise.
* src/atomic_ops/sysdeps/loadstore/short_aligned_atomic_load_store.h:
Likewise.
* src/atomic_ops/sysdeps/loadstore/atomic_load_store.h: Likewise.
* src/atomic_ops/sysdeps/loadstore/char_atomic_load_store.h: Likewise.
* src/atomic_ops/sysdeps/loadstore/int_atomic_load_store.h: Likewise.
* src/atomic_ops/sysdeps/loadstore/short_atomic_load_store.h:
Likewise.