negative phase imports

gistfile1.txt

$ cat for-syntax.ss
(import (phi: -1 :tmp/for-template))

(displayln "for-syntax")

$ cat for-template.ss
(displayln "for-template")

$ cat program.ss
(import (phi: +1 :tmp/for-syntax))
(export main)
(def (main . args)
  (void))

$ gxc for-syntax.ss for-template.ss

$ gxc -exe -o program program.ss 
for-syntax

$ ./program
for-template