[glibmm] Meson build: Add missing Glib::Value and Variant documentation

[Kjell Ahlstedt <kjellahl src gnome org>]

commit 6d07bfe291edf7dc62bbf088f6002f604353b684
Author: Kjell Ahlstedt <kjellahlstedt gmail com>
Date:   Sun Sep 13 19:54:37 2020 +0200

    Meson build: Add missing Glib::Value and Variant documentation
    
    The value_basictypes.h and variant_basictypes.h files, which are generated
    from .m4 files, were not included in the input to Doxygen.

 docs/reference/meson.build | 6 +++++-
 glib/glibmm/meson.build    | 4 ++--
 2 files changed, 7 insertions(+), 3 deletions(-)
---
diff --git a/docs/reference/meson.build b/docs/reference/meson.build
index 790d1434..2ea2cc71 100644
--- a/docs/reference/meson.build
+++ b/docs/reference/meson.build
@@ -3,7 +3,8 @@
 # Input: built_files_root, project_source_root, glibmm_pcname, giomm_pcname,
 #        glibmm_hg_ccg_basenames, giomm_hg_ccg_basenames, build_documentation,
 #        glibmm_extra_h_files, giomm_extra_h_files, glibmm_built_h_file_targets,
-#        giomm_built_h_file_targets, install_datadir,python3, doc_reference_py
+#        giomm_built_h_file_targets, glibmm_h_m4_files, install_datadir,
+#        python3, doc_reference_py
 # Output: install_docdir, install_devhelpdir
 
 tag_file_modules = [
@@ -71,6 +72,9 @@ built_h_files = []
 foreach file : glibmm_hg_ccg_basenames
   built_h_files += built_files_root / 'glib' / 'glibmm' / file + '.h'
 endforeach
+foreach file : glibmm_h_m4_files
+  built_h_files += built_files_root / 'glib' / 'glibmm' / file
+endforeach
 foreach file : giomm_hg_ccg_basenames
   built_h_files += built_files_root / 'gio' / 'giomm' / file + '.h'
 endforeach
diff --git a/glib/glibmm/meson.build b/glib/glibmm/meson.build
index 0074634e..b24fea4d 100644
--- a/glib/glibmm/meson.build
+++ b/glib/glibmm/meson.build
@@ -3,9 +3,9 @@
 # Input: glibmm_build_dep, glibmm_pcname, maintainer_mode, project_source_root,
 #        generate_binding_py, handle_built_files_py, m4_files, pm_files,
 #        glibmm_libversion, install_includedir, python3, glibmm_rc, gmmproc_dir,
-#        is_host_windows, gendef, gmmproc, generate_wrap_init_pl, glibmm_libname
+#        is_host_windows, gmmproc, generate_wrap_init_pl, glibmm_libname
 # Output: glibmm_hg_ccg_basenames, glibmm_extra_h_files, built_files_root,
-#         glibmm_built_h_file_targets, glibmm_dep
+#         glibmm_built_h_file_targets, glibmm_h_m4_files, glibmm_dep
 
 glibmm_defs_basefiles = [
   'glib.defs',