Similar to the InputLayout init, this adds a small helper type to act
as a wrapper around shader init data (binary and size).

This also adds error trapping to the blit shader compilation. It also
removes the LazyResource2 class, and the CompileXS helper methods.

BUG=angleproject:2034

Change-Id: I3fd718393c8a0250e4263890f00d0e9147ec9567
Reviewed-on: https://chromium-review.googlesource.com/506776Reviewed-by: Geoff Lang <geofflang@chromium.org>
Reviewed-by: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
Commit-Queue: Jamie Madill <jmadill@chromium.org>