try to speed-up maprect + round2i + contains

We call roundOut in a few places. If we can get SkNx::Ceil we could efficiently implement that as well.

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search?issue=2133413002
CQ_INCLUDE_TRYBOTS=client.skia:Test-Ubuntu-GCC-GCE-CPU-AVX2-x86_64-Release-SKNX_NO_SIMD-Trybot

Review-Url: https://codereview.chromium.org/2133413002
8 files changed