Metal: Add shadow sampler overloads for textureProj[Offset] Added compile guards because sample_compare with bias is not defined for older MSL versions. Fixed: angleproject:354101888 Change-Id: I3972fabc9ebe7b7475343438272e57dcfed007f4 Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/5828944 Reviewed-by: Kimmo Kinnunen <kkinnunen@apple.com> Commit-Queue: Alexey Knyazev <lexa.knyazev@gmail.com> Reviewed-by: Geoff Lang <geofflang@chromium.org>