[glib] Do not build utf8_encode on CARBON platform

[Philip Withnall <pwithnall src gnome org>]

commit 929e1b1fde638bdfded4faa460f86c8d5e15d3e8
Author: Daniel Macks <dmacks netspace org>
Date:   Mon Mar 20 10:22:15 2017 -0400

    Do not build utf8_encode on CARBON platform
    
    utf8_encode is not used by g_utf8_collate_key on this platform.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=780306

 glib/gunicollate.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/glib/gunicollate.c b/glib/gunicollate.c
index 4fca634..5ba6762 100644
--- a/glib/gunicollate.c
+++ b/glib/gunicollate.c
@@ -159,7 +159,7 @@ g_utf8_collate (const gchar *str1,
   return result;
 }
 
-#if defined(__STDC_ISO_10646__) || defined(HAVE_CARBON)
+#if defined(__STDC_ISO_10646__)
 /* We need UTF-8 encoding of numbers to encode the weights if
  * we are using wcsxfrm. However, we aren't encoding Unicode
  * characters, so we can't simply use g_unichar_to_utf8.
@@ -206,7 +206,7 @@ utf8_encode (char *buf, wchar_t val)
 
   return retval;
 }
-#endif /* __STDC_ISO_10646__ || HAVE_CARBON */
+#endif /* __STDC_ISO_10646__ */
 
 #ifdef HAVE_CARBON