Fix 'unknown attribute no_sanitize' compiler warning for GCC

Fix 'unknown attribute no_sanitize' compiler warning for GCC
(fix commits 9020c5db, 6a3eee47, c058d9dc, 637f7fe1)

* src/atomic_ops.h [!__has_feature && __SANITIZE_ADDRESS__]
(AO_ADDRESS_SANITIZER): Define.
* src/atomic_ops.h [!AO_ATTR_NO_SANITIZE_MEMORY && AO_MEMORY_SANITIZER
&& !AO_CLANG_PREREQ(3,8)] (AO_ATTR_NO_SANITIZE_MEMORY): Define to
__attribute__((no_sanitize_memory)).
* src/atomic_ops.h [!AO_ATTR_NO_SANITIZE_THREAD && AO_THREAD_SANITIZER
&& !AO_CLANG_PREREQ(3,8)] (AO_ATTR_NO_SANITIZE_THREAD): Define to
__attribute__((no_sanitize_thread)).