Use rb_ident_hash_new instead of rb_hash_new_compare_by_id

The latter is same as the former, removed the duplicate function.

ext/coverage/coverage.c

@@ -54,7 +54,7 @@ rb_coverage_start(int argc, VALUE *argv, VALUE klass)
     }
 
     if (mode & COVERAGE_TARGET_METHODS) {
-	me2counter = rb_hash_new_compare_by_id();
+	me2counter = rb_ident_hash_new();
     }
     else {
 	me2counter = Qnil;

hash.c

@@ -1364,14 +1364,6 @@ rb_hash_new(void)
     return hash_alloc(rb_cHash);
 }
 
-VALUE
-rb_hash_new_compare_by_id(void)
-{
-    VALUE hash = rb_hash_new();
-    RHASH_ST_TABLE_SET(hash, rb_init_identtable());
-    return hash;
-}
-
 MJIT_FUNC_EXPORTED VALUE
 rb_hash_new_with_size(st_index_t size)
 {

internal.h

@@ -1605,9 +1605,6 @@ struct st_table *rb_hash_tbl_raw(VALUE hash);
 #endif
 
 VALUE rb_hash_new_with_size(st_index_t size);
-RUBY_SYMBOL_EXPORT_BEGIN
-VALUE rb_hash_new_compare_by_id(void);
-RUBY_SYMBOL_EXPORT_END
 VALUE rb_hash_has_key(VALUE hash, VALUE key);
 VALUE rb_hash_default_value(VALUE hash, VALUE key);
 VALUE rb_hash_set_default_proc(VALUE hash, VALUE proc);

variable.c

@@ -2020,7 +2020,7 @@ rb_autoload_str(VALUE mod, ID id, VALUE file)
     }
     file = rb_fstring(file);
     if (!autoload_featuremap) {
-        autoload_featuremap = rb_hash_new_compare_by_id();
+        autoload_featuremap = rb_ident_hash_new();
         rb_obj_hide(autoload_featuremap);
         rb_gc_register_mark_object(autoload_featuremap);
     }

vm_eval.c

@@ -2028,7 +2028,7 @@ rb_catch_obj(VALUE t, VALUE (*func)(), VALUE data)
 static void
 local_var_list_init(struct local_var_list *vars)
 {
-    vars->tbl = rb_hash_new_compare_by_id();
+    vars->tbl = rb_ident_hash_new();
     RBASIC_CLEAR_CLASS(vars->tbl);
 }