Based on experimenting with Uniscribe to extract grammar and categories.
Failures down from 44 to 35:
KHMER: 299089 out of 299124 tests passed. 35 failed (0.0117008%)
We still don't enforce the one-matra rule pre-decomposition, but enforce
an order and one-matra-per-position post-decomposition.
https://github.com/harfbuzz/harfbuzz/issues/667
Some clang versions define static_assert as a macro apparently, so we cannot
redefine it...
This reverts commit 94bfea0ce6.
This reverts commit 4e62627831.
Behdad Esfahbod