[gtk+] gtk/gtkentry.c: Fix build on pre-C99

[Chun-wei Fan <fanchunwei src gnome org>]

commit 0e9f24b5a47dff33c681b055df304bda3018c7f1
Author: Chun-wei Fan <fanchunwei src gnome org>
Date:   Mon Feb 15 17:22:00 2016 +0800

    gtk/gtkentry.c: Fix build on pre-C99
    
    This file now uses nearbyint(), so include fallback-c89.c so that
    compilers that don't provide the function will not get upset.

 gtk/gtkentry.c |    3 ++-
 1 files changed, 2 insertions(+), 1 deletions(-)
---
diff --git a/gtk/gtkentry.c b/gtk/gtkentry.c
index dad0869..556db72 100644
--- a/gtk/gtkentry.c
+++ b/gtk/gtkentry.c
@@ -28,7 +28,6 @@
 
 #include "config.h"
 
-#include <math.h>
 #include <string.h>
 
 #include "gtkbindings.h"
@@ -74,6 +73,8 @@
 
 #include "a11y/gtkentryaccessible.h"
 
+#include "fallback-c89.c"
+
 /**
  * SECTION:gtkentry
  * @Short_description: A single line text entry field