ART: Add cutout for Character.toLower/UpperCase

Add support for ASCII codepoint toLowerCase/toUpperCase. Those
inputs are easy, and generally sufficient.

Allows to compile-time initialize:
* android.text.Html$HtmlParser
* java.util.UUID$Holder
* sun.security.ec.ECKeyFactory

Bug: 27265238
Change-Id: I0f164a7df4f26c0b266cef230e36f6ca3af20bde