Disallow variables of type 'void'.

Change-Id: I209119e6c74ca54dd6021b6dec4775fc7b66adeb
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/472448
Commit-Queue: John Stiles <johnstiles@google.com>
Auto-Submit: John Stiles <johnstiles@google.com>
Reviewed-by: Brian Osman <brianosman@google.com>
3 files changed