cv89 doesn’t work with b

[silmeth]

When trying to use cv89 (character variant which places a dot above the combining overline u+0301 diacritic), it doesn’t work if it’s placed over the letter b (but works eg. with a).

That’s annoying for Irish where b + overline / suspension stroke above it + lenition dot is a fairly common combination.

Doing b + combining overline + combining dot above doesn’t produce the desired output either:

(I’d expect the dot to be placed above the line)

[psb1558]

I've added an anchor so that (after the next release) the sequence b U+0305 U+0307 will produce the effect you want. I'll see if I can make cv89 work too, before the next release.