Remove SkIRect::EmptyIRect

Replace with SkIRect::MakeEmpty.

Docs-Preview: https://skia.org/?cl=262382
Change-Id: I001cc76f4af223490be3734bb461ab4fca36d710
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/262382
Reviewed-by: Mike Klein <mtklein@google.com>
Commit-Queue: Brian Salomon <bsalomon@google.com>
15 files changed