[subset] Graduate L1 instancing API from experimental

Fixes https://github.com/harfbuzz/harfbuzz/issues/3926

docs/harfbuzz-sections.txt

@@ -773,6 +773,8 @@ hb_subset_input_get_flags
 hb_subset_input_unicode_set
 hb_subset_input_glyph_set
 hb_subset_input_set
+hb_subset_input_pin_axis_location
+hb_subset_input_pin_axis_to_default
 hb_subset_or_fail
 hb_subset_plan_create_or_fail
 hb_subset_plan_reference
@@ -792,7 +794,5 @@ hb_subset_plan_t
 hb_link_t
 hb_object_t
 hb_subset_repack_or_fail
-hb_subset_input_pin_axis_location
-hb_subset_input_pin_axis_to_default
 hb_subset_input_override_name_table
 </SECTION>

perf/benchmark-subset.cc

@@ -167,7 +167,6 @@ static void BM_subset (benchmark::State &state,
     break;
 
     case instance:
-#ifdef HB_EXPERIMENTAL_API
     {
       hb_set_t* all_codepoints = hb_set_create ();
       hb_face_collect_unicodes (face, all_codepoints);
@@ -179,7 +178,6 @@ static void BM_subset (benchmark::State &state,
                                            test_input.instance_opts[i].axis_tag,
                                            test_input.instance_opts[i].axis_value);
     }
-#endif
     break;
   }
 
@@ -249,9 +247,7 @@ int main(int argc, char** argv)
 
   TEST_OPERATION (subset_glyphs, benchmark::kMillisecond);
   TEST_OPERATION (subset_codepoints, benchmark::kMillisecond);
-#ifdef HB_EXPERIMENTAL_API
   TEST_OPERATION (instance, benchmark::kMillisecond);
-#endif
 
 #undef TEST_OPERATION
 

src/gen-def.py

@@ -20,8 +20,6 @@ if '--experimental-api' not in sys.argv:
 	# Move these to harfbuzz-sections.txt when got stable
 	experimental_symbols = \
 """hb_subset_repack_or_fail
-hb_subset_input_pin_axis_location
-hb_subset_input_pin_axis_to_default
 hb_subset_input_override_name_table
 """.splitlines ()
 	symbols = [x for x in symbols if x not in experimental_symbols]

src/hb-subset-input.cc

@@ -395,7 +395,6 @@ hb_subset_input_get_user_data (const hb_subset_input_t *input,
   return hb_object_get_user_data (input, key);
 }
 
-#ifdef HB_EXPERIMENTAL_API
 #ifndef HB_NO_VAR
 /**
  * hb_subset_input_pin_axis_to_default: (skip)
@@ -406,7 +405,7 @@ hb_subset_input_get_user_data (const hb_subset_input_t *input,
  *
  * Return value: `true` if success, `false` otherwise
  *
- * Since: EXPERIMENTAL
+ * Since: REPLACEME
  **/
 HB_EXTERN hb_bool_t
 hb_subset_input_pin_axis_to_default (hb_subset_input_t  *input,
@@ -430,7 +429,7 @@ hb_subset_input_pin_axis_to_default (hb_subset_input_t  *input,
  *
  * Return value: `true` if success, `false` otherwise
  *
- * Since: EXPERIMENTAL
+ * Since: REPLACEME
  **/
 HB_EXTERN hb_bool_t
 hb_subset_input_pin_axis_location (hb_subset_input_t  *input,
@@ -446,7 +445,6 @@ hb_subset_input_pin_axis_location (hb_subset_input_t  *input,
   return input->axes_location->set (axis_tag, val);
 }
 #endif
-#endif
 
 /**
  * hb_subset_preprocess:

src/hb-subset.h

@@ -165,8 +165,6 @@ HB_EXTERN void
 hb_subset_input_set_flags (hb_subset_input_t *input,
 			   unsigned value);
 
-#ifdef HB_EXPERIMENTAL_API
-#ifndef HB_NO_VAR
 HB_EXTERN hb_bool_t
 hb_subset_input_pin_axis_to_default (hb_subset_input_t  *input,
 				     hb_face_t          *face,
@@ -177,8 +175,6 @@ hb_subset_input_pin_axis_location (hb_subset_input_t  *input,
 				   hb_face_t          *face,
 				   hb_tag_t            axis_tag,
 				   float               axis_value);
-#endif
-#endif
 
 #ifdef HB_EXPERIMENTAL_API
 HB_EXTERN hb_bool_t