Include ao_t_is_int.h from atomic_ops.h after first generalization if

Include ao_t_is_int.h from atomic_ops.h after first generalization if
AO_T_IS_INT (new macro) is defined in 'sysdeps' file

* src/atomic_ops.h (AO_T_IS_INT): Test macro after first
generalization, if set then include ao_t_is_int.h file and force
AO_GENERALIZE_TWICE.
* src/atomic_ops/sysdeps/gcc/hexagon.h (AO_T_IS_INT): Define new macro
instead of ao_t_is_int.h inclusion.
* src/atomic_ops/sysdeps/gcc/ia64.h (AO_T_IS_INT): Likewise.
* src/atomic_ops/sysdeps/gcc/m68k.h (AO_T_IS_INT): Likewise.
* src/atomic_ops/sysdeps/gcc/mips.h (AO_T_IS_INT): Likewise.
* src/atomic_ops/sysdeps/gcc/powerpc.h (AO_T_IS_INT): Likewise.
* src/atomic_ops/sysdeps/gcc/x86.h (AO_T_IS_INT): Likewise.
* src/atomic_ops/sysdeps/hpc/ia64.h (AO_T_IS_INT): Likewise.
* src/atomic_ops/sysdeps/msftc/x86.h (AO_T_IS_INT): Likewise.
* src/atomic_ops/sysdeps/sunc/x86.h (AO_T_IS_INT): Likewise.
* src/atomic_ops/sysdeps/gcc/powerpc.h: Add place-holder comment (in
case of ppc64).
* src/atomic_ops/sysdeps/gcc/hexagon.h: Do not include generalize.h
any longer (since ao_t_is_int.h is included from atomic_ops.h now).
* src/atomic_ops/sysdeps/gcc/ia64.h: Likewise.
* src/atomic_ops/sysdeps/hpc/ia64.h: Likewise.