Generated by:
http://git.savannah.gnu.org/cgit/sinhala.git/plain/utils/gen-unicode-sinhala.py

Merge tests from:
http://git.savannah.gnu.org/cgit/sinhala.git/plain/patches/icu-sinhala-rendering.txt

In Sinhala, Rakar is formed by Al-Lakuna,ZWJ,Ra.  If you put that at the
end of a Consonant,Matra syllable, you get a dotted-circle from
Uniscribe.  Apparently adding a ZWJ before the Al-Lakuna "fixes" that.
And people have been encoding that sequence...  So, allow a forced
"ZWJ,Virama,ZWJ,Ra" sequence at the of syllables.

Fixes some 100 or more of Sinhala failures.  Now at 622 only (0.23%).

POS_BASE can disappear if base ligated backward.  Define base as last
with position not after base.

Fixes a few hundred of Sinhala failures with Iskoola Pota.

In Sinhala, Reph is formed only explicitly, by the presence of a ZWJ.