[skshaper] Export CoreText shaper sources in public.bzl

Making these available for g3.

Change-Id: Ib6b9641557e123a663f51dadd27a3e57e6db3afc
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/654977
Commit-Queue: Ben Wagner <bungeman@google.com>
Auto-Submit: Florin Malita <fmalita@chromium.org>
Reviewed-by: Ben Wagner <bungeman@google.com>
1 file changed