v0.77 (2022-06-20)

Fix width of combining characters under ambiguous as wide.

When "Treat ambiguous character width as wide" was on, some combining
characters themselves were treated as wide character instead of
zero-width. The fix prevents splitting of grapheme, and indirectly
fixes the assertion error when drawing combining character alone.
Yet the assertion is commented out as the fix cannot cope with
multiple combining characters at present. This effectively reverting
to the v0.76 behavior of skipping the assertion on release build.

The current head of main may not have the problem that causes the
assertion error (the assertion code itself is not in the original),
but I am not sure which commit should be picked.