8054203: add regression tests for JDK vs ICU layout

[Steven R. Loomis]

https://bugs.openjdk.java.net/browse/JDK-8054203

(Phil, others - I didn't see a HarfBuzz component, so I hope this is
right- I created a label "harfbuzz")
  subcomponent 2d,  label harfbuzz

Anyways, I have code for this already that I used when doing other fixes
to the layout code.
I'd like to take this one.

Note some interesting things:

* the generator for the data lives in ICU right now.  TBD document how
to create it

* It's font dependent.  We should use create it not just against
"interesting" fonts that devs won't have access to, but also against
fonts that either ship with JDK and/or are easily available (Google noto
come to mind).