Define AO_int_X operations for ARM and avr32

Define AO_int_X operations for ARM and avr32

* src/atomic_ops/sysdeps/armcc/arm_v6.h (AO_T_IS_INT): Define macro
(signifying that AO_t is in fact int and, thus, defining AO_int_...
primitives).
* src/atomic_ops/sysdeps/gcc/arm.h b/src/atomic_ops/sysdeps/gcc/arm.h
(AO_T_IS_INT): Likewise.
* src/atomic_ops/sysdeps/gcc/avr32.h (AO_T_IS_INT): Likewise.
* src/atomic_ops/sysdeps/msftc/arm.h (AO_T_IS_INT): Likewise.
* src/atomic_ops/sysdeps/gcc/arm.h (AO_T_IS_INT): Add FIXME
(AO_T_IS_INT should be defined conditionally on adding 64-bit ABI
support).
* src/atomic_ops/sysdeps/gcc/mips.h (AO_T_IS_INT): Likewise.