glib, gmodule, gobject: Add generated headers to the lib dependency

This requires changing them from being generated sources at compile time
to custom targets, but it also ensures that they are actually there when
needed, in fact currently we may instead try to compile files that requires
them without having been generated yet.

See: https://gitlab.gnome.org/GNOME/glib/-/jobs/2346914 (glib)
See: https://gitlab.gnome.org/GNOME/glib/-/jobs/2344802 (gmodule)
See: https://gitlab.gnome.org/GNOME/glib/-/jobs/2345205 (gobject)

gobject/meson.build

@@ -23,16 +23,20 @@ gobject_install_headers = files(
   'gobjectnotifyqueue.c', # sic
 )
 
-gvisibility_h = configure_file(
+gobject_sources = []
+
+gvisibility_h = custom_target(
   output: 'gobject-visibility.h',
   command: [gen_visibility_macros, meson.project_version(), 'visibility-macros', 'GOBJECT', '@OUTPUT@'],
+  install: true,
+  install_dir: glib_includedir / 'gobject',
+  install_tag : 'devel',
 )
-
-gobject_install_headers += gvisibility_h
+gobject_sources += gvisibility_h
 
 install_headers(gobject_install_headers, subdir : 'glib-2.0/gobject')
 
-gobject_sources = files(
+gobject_sources += files(
   'gatomicarray.c',
   'gbinding.c',
   'gbindinggroup.c',
@@ -128,8 +132,6 @@ glib_enumtypes_c = custom_target('glib_enumtypes_c',
              '--template', files('glib-enumtypes.c.template'),
              '@INPUT@'])
 
-glib_enumtypes_dep = declare_dependency(sources : [glib_enumtypes_h])
-
 # Expose as variable to be used by gobject-introspection
 # when it includes GLib as a subproject
 glib_types_h = files('glib-types.h')
@@ -159,7 +161,9 @@ pkg.generate(libgobject,
 
 libgobject_dep = declare_dependency(link_with : libgobject,
   include_directories : [gobjectinc],
-  dependencies : [libglib_dep, glib_enumtypes_dep])
+  sources : [gvisibility_h, glib_enumtypes_h],
+  dependencies : [libglib_dep],
+)
 meson.override_dependency('gobject-2.0', libgobject_dep)
 
 executable('gobject-query', 'gobject-query.c',