as: Abort

 
 7.1 '.abort'
 ============
 
 This directive stops the assembly immediately.  It is for compatibility
 with other assemblers.  The original idea was that the assembly language
 source would be piped into the assembler.  If the sender of the source
 quit, it could use this directive tells 'as' to quit also.  One day
 '.abort' will not be supported.