[Snek] [keith-packard/snek] 91ddd2: Use frexpf instead of frexp in snek-pow.c

[Keith Packard]

  Branch: refs/heads/master
  Home:   https://github.com/keith-packard/snek
  Commit: 91ddd23fd91fb9c4ef42421573072310da64c206
      https://github.com/keith-packard/snek/commit/91ddd23fd91fb9c4ef42421573072310da64c206
  Author: Keith Packard <keithp at keithp.com>
  Date:   2019-11-06 (Wed, 06 Nov 2019)

  Changed paths:
    M snek-pow.c

  Log Message:
  -----------
  Use frexpf instead of frexp in snek-pow.c

Avoid casting to double and back

Signed-off-by: Keith Packard <keithp at keithp.com>