[myanmar] Relax pwo-tone group a bit
This is broken sequence according to OpenType spec, Uniscribe,
and current HarfBuzz implementation. But Roozbeh says this
is a valid sequence, so allow it. There are multiple
"(DB As?)?" constructs in the grammar, but Roozbeh thinks only
this one needs changing.
Test case: 1014,1063,103A
Fixes https://bugs.freedesktop.org/show_bug.cgi?id=71949
diff --git a/src/hb-ot-shape-complex-myanmar-machine.rl b/src/hb-ot-shape-complex-myanmar-machine.rl
index 51d42dd..2ac3e89 100644
--- a/src/hb-ot-shape-complex-myanmar-machine.rl
+++ b/src/hb-ot-shape-complex-myanmar-machine.rl
@@ -70,7 +70,7 @@
medial_group = MY? MR? ((MW MH? | MH) As?)?;
main_vowel_group = VPre* VAbv* VBlw* A* (DB As?)?;
post_vowel_group = VPst MH? As* VAbv* A* (DB As?)?;
-pwo_tone_group = PT A* (DB As?)?;
+pwo_tone_group = PT A* DB? As?;
complex_syllable_tail = As* medial_group main_vowel_group post_vowel_group* pwo_tone_group* V* j?;
syllable_tail = (H | complex_syllable_tail);
