glib: move g_poll() replacement into glib-compat.h

We have a dedicated header file for wrappers to smooth over glib version
differences.  Move the g_poll() definition into glib-compat.h for
consistency.
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>
Signed-off-by: NMichael Tokarev <mjt@tls.msk.ru>
Cc: qemu-trivial@nongnu.org

include/glib-compat.h

@@ -24,4 +24,16 @@ static inline guint g_timeout_add_seconds(guint interval, GSourceFunc function,
 }
 #endif
 
+#if !GLIB_CHECK_VERSION(2, 20, 0)
+/*
+ * Glib before 2.20.0 doesn't implement g_poll, so wrap it to compile properly
+ * on older systems.
+ */
+static inline gint g_poll(GPollFD *fds, guint nfds, gint timeout)
+{
+    GMainContext *ctx = g_main_context_default();
+    return g_main_context_get_poll_func(ctx)(fds, nfds, timeout);
+}
+#endif
+
 #endif

include/qemu-common.h

@@ -124,18 +124,6 @@ int qemu_main(int argc, char **argv, char **envp);
 void qemu_get_timedate(struct tm *tm, int offset);
 int qemu_timedate_diff(struct tm *tm);
 
-#if !GLIB_CHECK_VERSION(2, 20, 0)
-/*
- * Glib before 2.20.0 doesn't implement g_poll, so wrap it to compile properly
- * on older systems.
- */
-static inline gint g_poll(GPollFD *fds, guint nfds, gint timeout)
-{
-    GMainContext *ctx = g_main_context_default();
-    return g_main_context_get_poll_func(ctx)(fds, nfds, timeout);
-}
-#endif
-
 /**
  * is_help_option:
  * @s: string to test