Do not include standard_ao_double_t.h where double-CAS is unimplemented

Do not include standard_ao_double_t.h where double-CAS is unimplemented

* src/atomic_ops/sysdeps/gcc/mips.h: Comment out include
standard_ao_double_t.h (since double-CAS is not implemented).
* src/atomic_ops/sysdeps/msftc/arm.h: Likewise.
* src/atomic_ops/sysdeps/gcc/mips.h: Add TODO item for
AO_compare_double_and_swap_double.
* src/atomic_ops/sysdeps/gcc/x86_64.h: Include standard_ao_double_t.h
only if AO_compare_double_and_swap_double_full defined.
* src/atomic_ops/sysdeps/msftc/x86_64.h: Likewise.
* src/atomic_ops/sysdeps/sunc/x86.h: Likewise.