[gtk/gtk-3-24] Fix visibiity of gdkselection-quartz.c exported gtk-only functions.

[John Ralls <jralls src gnome org>]

commit 235d28f02d54e6601cef51fec91d46961f64009e
Author: John Ralls <jralls ceridwen us>
Date:   Tue Dec 10 21:25:48 2019 -0800

    Fix visibiity of gdkselection-quartz.c exported gtk-only functions.
    
    Also ensure that gdkquartz-gtk-only.h is included in distribution
    tarballs.
    
    Failing to include gdkquartz-gtk-only.h in gdkselection-quartz.c
    caused the compiler to not set the extern storage class on the
    functions, in turn causing them to be not exported by libgdk-3.0.dylib.
    
    Fixes https://gitlab.gnome.org/GNOME/gtk/issues/32 again.

 gdk/quartz/Makefile.am           | 1 +
 gdk/quartz/gdkselection-quartz.c | 1 +
 2 files changed, 2 insertions(+)
---
diff --git a/gdk/quartz/Makefile.am b/gdk/quartz/Makefile.am
index 3007b199c4..141d931c64 100644
--- a/gdk/quartz/Makefile.am
+++ b/gdk/quartz/Makefile.am
@@ -60,6 +60,7 @@ libgdkinclude_HEADERS =       \
        gdkquartz.h
 
 libgdkquartzinclude_HEADERS =          \
+       gdkquartz-gtk-only.h            \
        gdkquartzcursor.h               \
        gdkquartzdevice-core.h          \
        gdkquartzdevicemanager-core.h   \
diff --git a/gdk/quartz/gdkselection-quartz.c b/gdk/quartz/gdkselection-quartz.c
index 20f65f960f..79f8374420 100644
--- a/gdk/quartz/gdkselection-quartz.c
+++ b/gdk/quartz/gdkselection-quartz.c
@@ -24,6 +24,7 @@
 #include "gdkproperty.h"
 #include "gdkquartz.h"
 #include "gdkinternal-quartz.h"
+#include "gdkquartz-gtk-only.h"
 
 gboolean
 _gdk_quartz_display_set_selection_owner (GdkDisplay *display,