[use] Implement Consonant_With_Stacker

Related to https://github.com/behdad/harfbuzz/issues/528

src/gen-use-table.py

@@ -178,6 +178,8 @@ def is_CONS_MOD(U, UISC, UGC):
 def is_CONS_SUB(U, UISC, UGC):
 	#SPEC-DRAFT return UISC == Consonant_Subjoined
 	return UISC == Consonant_Subjoined and UGC != Lo
+def is_CONS_WITH_STACKER(U, UISC, UGC):
+	return UISC == Consonant_With_Stacker
 def is_HALANT(U, UISC, UGC):
 	return UISC in [Virama, Invisible_Stacker]
 def is_HALANT_NUM(U, UISC, UGC):
@@ -199,9 +201,7 @@ def is_OTHER(U, UISC, UGC):
 def is_Reserved(U, UISC, UGC):
 	return UGC == 'Cn'
 def is_REPHA(U, UISC, UGC):
-	#return UISC == Consonant_Preceding_Repha
-	#SPEC-OUTDATED hack to categorize Consonant_With_Stacker and Consonant_Prefixed
-	return UISC in [Consonant_Preceding_Repha, Consonant_With_Stacker, Consonant_Prefixed]
+	return UISC in [Consonant_Preceding_Repha, Consonant_Prefixed]
 def is_SYM(U, UISC, UGC):
 	if U == 0x25CC: return False #SPEC-DRAFT
 	#SPEC-DRAFT return UGC in [So, Sc] or UISC == Symbol_Letter
@@ -230,6 +230,7 @@ use_mapping = {
 	'M':	is_CONS_MED,
 	'CM':	is_CONS_MOD,
 	'SUB':	is_CONS_SUB,
+	'CS':	is_CONS_WITH_STACKER,
 	'H':	is_HALANT,
 	'HN':	is_HALANT_NUM,
 	'ZWNJ':	is_ZWNJ,

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

@@ -86,6 +86,7 @@ VMPst	= 39; # VOWEL_MOD_POST
 VMPre	= 23; # VOWEL_MOD_PRE
 SMAbv	= 41; # SYM_MOD_ABOVE
 SMBlw	= 42; # SYM_MOD_BELOW
+CS	= 43; # CONS_WITH_STACKER
 
 
 consonant_modifiers = CMAbv* CMBlw* ((H B | SUB) VS? CMAbv? CMBlw*)*;
@@ -96,12 +97,12 @@ vowel_modifiers = VMPre* VMAbv* VMBlw* VMPst*;
 final_consonants = FAbv* FBlw* FPst* FM?;
 
 virama_terminated_cluster =
-	R? (B | GB) VS?
+	(R|CS)? (B | GB) VS?
 	consonant_modifiers
 	H
 ;
 standard_cluster =
-	R? (B | GB) VS?
+	(R|CS)? (B | GB) VS?
 	consonant_modifiers
 	medial_consonants
 	dependent_vowels

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

@@ -87,7 +87,8 @@ enum use_category_t {
   USE_VMPst	= 39,	/* VOWEL_MOD_POST */
   USE_VMPre	= 23,	/* VOWEL_MOD_PRE */
   USE_SMAbv	= 41,	/* SYM_MOD_ABOVE */
-  USE_SMBlw	= 42	/* SYM_MOD_BELOW */
+  USE_SMBlw	= 42,	/* SYM_MOD_BELOW */
+  USE_CS	= 43	/* CONS_WITH_STACKER */
 };
 
 HB_INTERNAL USE_TABLE_ELEMENT_TYPE

src/hb-ot-shape-complex-use-table.cc

@@ -19,6 +19,7 @@
 
 #define B	USE_B	/* BASE */
 #define CGJ	USE_CGJ	/* CGJ */
+#define CS	USE_CS	/* CONS_WITH_STACKER */
 #define FM	USE_FM	/* CONS_FINAL_MOD */
 #define GB	USE_GB	/* BASE_OTHER */
 #define H	USE_H	/* HALANT */
@@ -163,7 +164,7 @@ static const USE_TABLE_ELEMENT_TYPE use_table[] = {
   /* 0CC0 */  VAbv,  VPst,  VPst,  VPst,  VPst,     O,  VAbv,  VAbv,  VAbv,     O,  VAbv,  VAbv,  VAbv,     H,     O,     O,
   /* 0CD0 */     O,     O,     O,     O,     O,  VPst,  VPst,     O,     O,     O,     O,     O,     O,     O,     B,     O,
   /* 0CE0 */     B,     B,  VBlw,  VBlw,     O,     O,     B,     B,     B,     B,     B,     B,     B,     B,     B,     B,
-  /* 0CF0 */     O,     R,     R,     O,     O,     O,     O,     O,     O,     O,     O,     O,     O,     O,     O,     O,
+  /* 0CF0 */     O,    CS,    CS,     O,     O,     O,     O,     O,     O,     O,     O,     O,     O,     O,     O,     O,
 
   /* Malayalam */
 
@@ -467,7 +468,7 @@ static const USE_TABLE_ELEMENT_TYPE use_table[] = {
 
   /* Brahmi */
 
-  /* 11000 */ VMPst, VMAbv, VMPst,     R,     R,     B,     B,     B,     B,     B,     B,     B,     B,     B,     B,     B,
+  /* 11000 */ VMPst, VMAbv, VMPst,    CS,    CS,     B,     B,     B,     B,     B,     B,     B,     B,     B,     B,     B,
   /* 11010 */     B,     B,     B,     B,     B,     B,     B,     B,     B,     B,     B,     B,     B,     B,     B,     B,
   /* 11020 */     B,     B,     B,     B,     B,     B,     B,     B,     B,     B,     B,     B,     B,     B,     B,     B,
   /* 11030 */     B,     B,     B,     B,     B,     B,     B,     B,  VAbv,  VAbv,  VAbv,  VAbv,  VBlw,  VBlw,  VBlw,  VBlw,
@@ -729,6 +730,7 @@ hb_use_get_categories (hb_codepoint_t u)
 
 #undef B
 #undef CGJ
+#undef CS
 #undef FM
 #undef GB
 #undef H