[graphite] Add a fast SIMD Rect type

Implements a Rect type whose standard operations use float4. The intent
of this class is to make calculations on draw bounds as fast as
possible.

Change-Id: I3bdb219b242bb7097809507c345b613670ff386e
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/457136
Commit-Queue: Chris Dalton <csmartdalton@google.com>
Reviewed-by: Michael Ludwig <michaelludwig@google.com>
4 files changed