enums

[Doug Evans]

Johan Rydberg writes:
 > Ofcouse, here's the result:
 > 
 > ERROR: In procedure caar:
 > ERROR: Wrong type argument in position 1: ()

cgen needs to be more robust with bad input.
One might construct an argument that () should just be ignored
instead of flagged as an error.  dunno.

Take the line with () out.

 (define-enum
   (name e-exception)
   (comment "exception vectors")
>  ()
   (prefix E_)
   (values ("RESET") ("BUSERR" -) ("DPF" -) ("IPF" -) 
           ("EXTINT" -) ("ALIGN" -) ("ILLEGAL" -) ("PEINT" -)
           ("DTLBMISS" -) ("ITLBMISS" -) ("RRANGE" -) 
           ("SYSCALL" -) ("BREAK" -) ("RESERVED" -))
 )