Undefine internal macros that are defined solely for generic.h

Undefine internal macros that are defined solely for generic.h
(fix commits 03a0465f, 3c52619c, 66f7a4d3)

* src/atomic_ops/sysdeps/gcc/aarch64.h (AO_SKIPATOMIC_double_load,
AO_SKIPATOMIC_double_load_acquire): Undefine at the end of file.
* src/atomic_ops/sysdeps/gcc/arm.h (AO_SKIPATOMIC_ANY_and_ANY,
AO_SKIPATOMIC_ANY_or_ANY, AO_SKIPATOMIC_ANY_xor_ANY,
AO_SKIPATOMIC_char_store, AO_SKIPATOMIC_char_store_release,
AO_SKIPATOMIC_int_store, AO_SKIPATOMIC_int_store_release,
AO_SKIPATOMIC_short_store, AO_SKIPATOMIC_short_store_release,
AO_SKIPATOMIC_store, AO_SKIPATOMIC_store_release): Likewise.