[indic] Implement Consonent_With_Stacker

Fixes https://github.com/behdad/harfbuzz/issues/528

src/hb-ot-shape-complex-indic-machine.rl

@@ -57,6 +57,7 @@ Repha = 15;
 Ra    = 16;
 CM    = 17;
 Symbol= 18;
+CS    = 19;
 
 c = (C | Ra);			# is_consonant
 n = ((ZWNJ?.RS)? (N.N?)?);	# is_consonant_modifier
@@ -76,9 +77,9 @@ medial_group = CM?;
 halant_or_matra_group = (final_halant_group | (h.ZWJ)? matra_group{0,4}) (Coeng (cn|V))?;
 
 
-consonant_syllable =	Repha? (cn.halant_group){0,4} cn medial_group halant_or_matra_group syllable_tail;
+consonant_syllable =	(Repha|CS)? (cn.halant_group){0,4} cn medial_group halant_or_matra_group syllable_tail;
 vowel_syllable =	reph? V.n? (ZWJ | (halant_group.cn){0,4} medial_group halant_or_matra_group syllable_tail);
-standalone_cluster =	(Repha? PLACEHOLDER | reph? DOTTEDCIRCLE).n? (halant_group.cn){0,4} medial_group halant_or_matra_group syllable_tail;
+standalone_cluster =	((Repha|CS)? PLACEHOLDER | reph? DOTTEDCIRCLE).n? (halant_group.cn){0,4} medial_group halant_or_matra_group syllable_tail;
 symbol_cluster = 	symbol syllable_tail;
 broken_cluster =	reph? n? (halant_group.cn){0,4} medial_group halant_or_matra_group syllable_tail;
 other =			any;

src/hb-ot-shape-complex-indic-private.hh

@@ -60,7 +60,8 @@ enum indic_category_t {
   OT_Repha = 15, /* Atomically-encoded logical or visual repha. */
   OT_Ra = 16,
   OT_CM = 17,  /* Consonant-Medial. */
-  OT_Symbol = 18 /* Avagraha, etc that take marks (SM,A,VD). */
+  OT_Symbol = 18, /* Avagraha, etc that take marks (SM,A,VD). */
+  OT_CS = 19
 };
 
 #define MEDIAL_FLAGS (FLAG (OT_CM))
@@ -70,7 +71,7 @@ enum indic_category_t {
  * We treat Vowels and placeholders as if they were consonants.  This is safe because Vowels
  * cannot happen in a consonant syllable.  The plus side however is, we can call the
  * consonant syllable logic from the vowel syllable function and get it all right! */
-#define CONSONANT_FLAGS (FLAG (OT_C) | FLAG (OT_Ra) | MEDIAL_FLAGS | FLAG (OT_V) | FLAG (OT_PLACEHOLDER) | FLAG (OT_DOTTEDCIRCLE))
+#define CONSONANT_FLAGS (FLAG (OT_C) | FLAG (OT_CS) | FLAG (OT_Ra) | MEDIAL_FLAGS | FLAG (OT_V) | FLAG (OT_PLACEHOLDER) | FLAG (OT_DOTTEDCIRCLE))
 #define JOINER_FLAGS (FLAG (OT_ZWJ) | FLAG (OT_ZWNJ))
 #define HALANT_OR_COENG_FLAGS (FLAG (OT_H) | FLAG (OT_Coeng))
 
@@ -121,7 +122,7 @@ enum indic_syllabic_category_t {
   INDIC_SYLLABIC_CATEGORY_CONSONANT_PREFIXED		= OT_X, /* Don't care. */
   INDIC_SYLLABIC_CATEGORY_CONSONANT_SUBJOINED		= OT_CM,
   INDIC_SYLLABIC_CATEGORY_CONSONANT_SUCCEEDING_REPHA	= OT_N,
-  INDIC_SYLLABIC_CATEGORY_CONSONANT_WITH_STACKER	= OT_C,
+  INDIC_SYLLABIC_CATEGORY_CONSONANT_WITH_STACKER	= OT_CS,
   INDIC_SYLLABIC_CATEGORY_GEMINATION_MARK		= OT_SM,
   INDIC_SYLLABIC_CATEGORY_INVISIBLE_STACKER		= OT_Coeng,
   INDIC_SYLLABIC_CATEGORY_JOINER			= OT_ZWJ,

src/hb-ot-shape-complex-myanmar-machine.rl

@@ -41,7 +41,7 @@
 A    = 10;
 As   = 18;
 C    = 1;
-D    = 19;
+D    = 32;
 D0   = 20;
 DB   = 3;
 GB   = 11;
@@ -62,6 +62,7 @@ ZWJ  = 6;
 ZWNJ = 5;
 Ra   = 16;
 P    = 31;
+CS   = 19;
 
 j = ZWJ|ZWNJ;			# Joiners
 k = (Ra As H);			# Kinzi
@@ -76,7 +77,7 @@ 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);
 
-consonant_syllable =	k? (c|IV|D|GB).VS? (H (c|IV).VS?)* syllable_tail;
+consonant_syllable =	(k|CS)? (c|IV|D|GB).VS? (H (c|IV).VS?)* syllable_tail;
 punctuation_cluster = 	P V;
 broken_cluster =	k? VS? syllable_tail;
 other =			any;

src/hb-ot-shape-complex-myanmar.cc

@@ -130,8 +130,7 @@ enum syllable_type_t {
 /* Note: This enum is duplicated in the -machine.rl source file.
  * Not sure how to avoid duplication. */
 enum myanmar_category_t {
-  OT_As  = 18, /* Asat */
-  OT_D   = 19, /* Digits except zero */
+  OT_As  = 18,  /* Asat */
   OT_D0  = 20, /* Digit zero */
   OT_DB  = OT_N, /* Dot below */
   OT_GB  = OT_PLACEHOLDER,
@@ -145,7 +144,8 @@ enum myanmar_category_t {
   OT_VPre = 28,
   OT_VPst = 29,
   OT_VS   = 30, /* Variation selectors */
-  OT_P    = 31  /* Punctuation */
+  OT_P    = 31, /* Punctuation */
+  OT_D    = 32, /* Digits except zero */
 };