extconf.rb in pitchfork-0.14.0

- old
+ new

@@ -1,11 +1,13 @@
 # -*- encoding: binary -*-
 # frozen_string_literal: true
 require 'mkmf'
 
+append_cflags("-fvisibility=hidden")
 have_const("PR_SET_CHILD_SUBREAPER", "sys/prctl.h")
 have_func("rb_enc_interned_str", "ruby.h") # Ruby 3.0+
 have_func("rb_io_descriptor", "ruby.h") # Ruby 3.1+
+have_func("getpagesize", "unistd.h")
 
 if RUBY_VERSION.start_with?('3.0.')
   # https://bugs.ruby-lang.org/issues/18772
   $CFLAGS << ' -DRB_ENC_INTERNED_STR_NULL_CHECK=1 '
 else