build: Deprecate an option

Rename the demos option to build-demos, to match
the other options for building optional parts.

meson.build

@@ -753,7 +753,7 @@ subdir('gdk')
 subdir('gsk')
 subdir('gtk')
 subdir('modules')
-if get_option('demos')
+if get_option('build-demos')
   subdir('demos')
 endif
 subdir('tools')
@@ -860,7 +860,7 @@ if not meson.is_cross_build()
   gnome.post_install(
     glib_compile_schemas: true,
     gio_querymodules: gio_module_dirs,
-    gtk_update_icon_cache: get_option('demos'),
+    gtk_update_icon_cache: get_option('build-demos'),
   )
 else
   message('Not executing post-install steps automatically when cross compiling')
@@ -901,7 +901,7 @@ summary('Documentation', get_option('gtk_doc'), section: 'Build')
 summary('Man pages', get_option('man-pages'), section: 'Build')
 summary('Testsuite', get_option('build-testsuite'), section: 'Build')
 summary('Tests', get_option('build-tests'), section: 'Build')
-summary('Demos', get_option('demos'), section: 'Build')
+summary('Demos', get_option('build-demos'), section: 'Build')
 summary('Examples', get_option('build-examples'), section: 'Build')
 
 # Directories

meson_options.txt

@@ -108,17 +108,22 @@ option('introspection',
 
 # Demos, examples and tests
 
-option('demos',
-       type: 'boolean',
-       value: true,
-       description : 'Build demo programs')
-
 option('profile',
        type: 'combo',
        choices: [ 'default', 'devel' ],
        value: 'default',
        description : 'Profile to use for demos')
 
+option('build-demos',
+       type: 'boolean',
+       value: true,
+       description : 'Build demo programs')
+
+option('demos',
+       type: 'boolean',
+       value: true,
+       deprecated: 'build-demos')
+
 option('build-testsuite',
        type: 'boolean',
        value: true,