meson.build: use built-in variable substitution handling instead of sed

Generated outputs are identical

Signed-off-by: Peter Hutterer <peter.hutterer@who-t.net>

include/X11/meson.build

@@ -18,15 +18,13 @@ elif cc.has_member('fd_set', '__fds_bits', prefix: fd_set_headers)
 else
     error('Your fd_set is too weird.')
 endif
-custom_target('Xpoll.h',
-              capture : true,
-              install : true,
-              install_dir : get_option('includedir') + '/X11',
-              input : 'Xpoll.h.in',
-              output : 'Xpoll.h',
-              command : [ sed,
-                          's/@USE_FDS_BITS@/' + fds_bits + '/g',
-                          '@INPUT@'])
+xpoll_config = configuration_data()
+xpoll_config.set('USE_FDS_BITS', fds_bits)
+configure_file(input : 'Xpoll.h.in',
+               output : 'Xpoll.h',
+               install : true,
+               install_dir : get_option('includedir') + '/X11',
+               configuration: xpoll_config)
 
 install_headers(
     'ap_keysym.h',

meson.build

@@ -20,7 +20,6 @@
 
 project('xorgproto', 'c', license : 'MIT', version : '2021.3')
 cc = meson.get_compiler('c')
-sed = find_program('sed')
 
 pcs = [
         'applewmproto',