[indic/khmer] Remove use of global constructors

Alternative woul have been to resurrect F_COMBINE that I removed in
70136a78

But this does it for now.  I'm not sure why check-static-inits.sh didn't
catch this before.  Clang -Weverything bot did:

  CXX      libharfbuzz_la-hb-ot-shape-complex-indic.lo
hb-ot-shape-complex-indic.cc:99:1: warning: declaration requires a global constructor [-Wglobal-constructors]
indic_features[] =
^
1 warning generated.
  CXX      libharfbuzz_la-hb-ot-shape-complex-khmer.lo
hb-ot-shape-complex-khmer.cc:36:1: warning: declaration requires a global constructor [-Wglobal-constructors]
khmer_features[] =
^
1 warning generated.

src/hb-ot-map.hh

@@ -174,11 +174,13 @@ enum hb_ot_map_feature_flags_t
   F_MANUAL_ZWNJ		= 0x0004u, /* Don't skip over ZWNJ when matching **context**. */
   F_MANUAL_ZWJ		= 0x0008u, /* Don't skip over ZWJ when matching **input**. */
   F_MANUAL_JOINERS	= F_MANUAL_ZWNJ | F_MANUAL_ZWJ,
+  F_GLOBAL_MANUAL_JOINERS= F_GLOBAL | F_MANUAL_JOINERS,
   F_GLOBAL_SEARCH	= 0x0010u, /* If feature not found in LangSys, look for it in global feature list and pick one. */
   F_RANDOM		= 0x0020u  /* Randomly select a glyph from an AlternateSubstFormat1 subtable. */
 };
 HB_MARK_AS_FLAG_T (hb_ot_map_feature_flags_t);
 
+
 struct hb_ot_map_feature_t
 {
   hb_tag_t tag;

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

@@ -102,29 +102,29 @@ indic_features[] =
    * Basic features.
    * These features are applied in order, one at a time, after initial_reordering.
    */
-  {HB_TAG('n','u','k','t'), F_GLOBAL | F_MANUAL_JOINERS},
-  {HB_TAG('a','k','h','n'), F_GLOBAL | F_MANUAL_JOINERS},
-  {HB_TAG('r','p','h','f'), F_NONE   | F_MANUAL_JOINERS},
-  {HB_TAG('r','k','r','f'), F_GLOBAL | F_MANUAL_JOINERS},
-  {HB_TAG('p','r','e','f'), F_NONE   | F_MANUAL_JOINERS},
-  {HB_TAG('b','l','w','f'), F_NONE   | F_MANUAL_JOINERS},
-  {HB_TAG('a','b','v','f'), F_NONE   | F_MANUAL_JOINERS},
-  {HB_TAG('h','a','l','f'), F_NONE   | F_MANUAL_JOINERS},
-  {HB_TAG('p','s','t','f'), F_NONE   | F_MANUAL_JOINERS},
-  {HB_TAG('v','a','t','u'), F_GLOBAL | F_MANUAL_JOINERS},
-  {HB_TAG('c','j','c','t'), F_GLOBAL | F_MANUAL_JOINERS},
+  {HB_TAG('n','u','k','t'), F_GLOBAL_MANUAL_JOINERS},
+  {HB_TAG('a','k','h','n'), F_GLOBAL_MANUAL_JOINERS},
+  {HB_TAG('r','p','h','f'),        F_MANUAL_JOINERS},
+  {HB_TAG('r','k','r','f'), F_GLOBAL_MANUAL_JOINERS},
+  {HB_TAG('p','r','e','f'),        F_MANUAL_JOINERS},
+  {HB_TAG('b','l','w','f'),        F_MANUAL_JOINERS},
+  {HB_TAG('a','b','v','f'),        F_MANUAL_JOINERS},
+  {HB_TAG('h','a','l','f'),        F_MANUAL_JOINERS},
+  {HB_TAG('p','s','t','f'),        F_MANUAL_JOINERS},
+  {HB_TAG('v','a','t','u'), F_GLOBAL_MANUAL_JOINERS},
+  {HB_TAG('c','j','c','t'), F_GLOBAL_MANUAL_JOINERS},
   /*
    * Other features.
    * These features are applied all at once, after final_reordering.
    * Default Bengali font in Windows for example has intermixed
    * lookups for init,pres,abvs,blws features.
    */
-  {HB_TAG('i','n','i','t'), F_NONE   | F_MANUAL_JOINERS},
-  {HB_TAG('p','r','e','s'), F_GLOBAL | F_MANUAL_JOINERS},
-  {HB_TAG('a','b','v','s'), F_GLOBAL | F_MANUAL_JOINERS},
-  {HB_TAG('b','l','w','s'), F_GLOBAL | F_MANUAL_JOINERS},
-  {HB_TAG('p','s','t','s'), F_GLOBAL | F_MANUAL_JOINERS},
-  {HB_TAG('h','a','l','n'), F_GLOBAL | F_MANUAL_JOINERS},
+  {HB_TAG('i','n','i','t'),        F_MANUAL_JOINERS},
+  {HB_TAG('p','r','e','s'), F_GLOBAL_MANUAL_JOINERS},
+  {HB_TAG('a','b','v','s'), F_GLOBAL_MANUAL_JOINERS},
+  {HB_TAG('b','l','w','s'), F_GLOBAL_MANUAL_JOINERS},
+  {HB_TAG('p','s','t','s'), F_GLOBAL_MANUAL_JOINERS},
+  {HB_TAG('h','a','l','n'), F_GLOBAL_MANUAL_JOINERS},
   /*
    * Positioning features.
    * We don't care about the types.

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

@@ -39,19 +39,19 @@ khmer_features[] =
    * Basic features.
    * These features are applied in order, one at a time, after reordering.
    */
-  {HB_TAG('p','r','e','f'), F_NONE   | F_MANUAL_JOINERS},
-  {HB_TAG('b','l','w','f'), F_NONE   | F_MANUAL_JOINERS},
-  {HB_TAG('a','b','v','f'), F_NONE   | F_MANUAL_JOINERS},
-  {HB_TAG('p','s','t','f'), F_NONE   | F_MANUAL_JOINERS},
-  {HB_TAG('c','f','a','r'), F_NONE   | F_MANUAL_JOINERS},
+  {HB_TAG('p','r','e','f'), F_MANUAL_JOINERS},
+  {HB_TAG('b','l','w','f'), F_MANUAL_JOINERS},
+  {HB_TAG('a','b','v','f'), F_MANUAL_JOINERS},
+  {HB_TAG('p','s','t','f'), F_MANUAL_JOINERS},
+  {HB_TAG('c','f','a','r'), F_MANUAL_JOINERS},
   /*
    * Other features.
    * These features are applied all at once.
    */
-  {HB_TAG('p','r','e','s'), F_GLOBAL | F_MANUAL_JOINERS},
-  {HB_TAG('a','b','v','s'), F_GLOBAL | F_MANUAL_JOINERS},
-  {HB_TAG('b','l','w','s'), F_GLOBAL | F_MANUAL_JOINERS},
-  {HB_TAG('p','s','t','s'), F_GLOBAL | F_MANUAL_JOINERS},
+  {HB_TAG('p','r','e','s'), F_GLOBAL_MANUAL_JOINERS},
+  {HB_TAG('a','b','v','s'), F_GLOBAL_MANUAL_JOINERS},
+  {HB_TAG('b','l','w','s'), F_GLOBAL_MANUAL_JOINERS},
+  {HB_TAG('p','s','t','s'), F_GLOBAL_MANUAL_JOINERS},
   /*
    * Positioning features.
    * We don't care about the types.