Annul a pointer to an Object astAnnul
This function also decrements the Object’
s RefCount attribute by one. If
this attribute reaches zero (which happens when the last pointer to the
Object is annulled), then the Object is deleted.
This function will attempt to annul the pointer even if the Object is not currently locked by the calling thread (see astLock).
This function attempts to execute even if the AST error status is set on entry, although no further error report will be made if it subsequently fails under these circumstances. In particular, it will fail if the pointer suppled is not valid, but this will only be reported if the error status is clear on entry.