Program: Move more common code to ProgramLinkedResources. Refactoring change only. Bug: angleproject:5496 Change-Id: Ic1c8301a070e91ad28791c23831b8236058ab9ab Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2606535 Commit-Queue: Jamie Madill <jmadill@chromium.org> Reviewed-by: Tim Van Patten <timvp@google.com> Reviewed-by: Shahbaz Youssefi <syoussefi@chromium.org>