[pango] Fix build on OS X

[Matthias Clasen <matthiasc src gnome org>]

commit 9cb49a3e224bbd5a3e6630aa053e516ecbc46083
Author: Matthias Clasen <mclasen redhat com>
Date:   Mon Sep 12 23:36:11 2016 -0400

    Fix build on OS X
    
    https://bugzilla.gnome.org/show_bug.cgi?id=770729

 pango/pangocoretext-fontmap.c |    4 ++--
 1 files changed, 2 insertions(+), 2 deletions(-)
---
diff --git a/pango/pangocoretext-fontmap.c b/pango/pangocoretext-fontmap.c
index 0d7d793..6cd9fe9 100644
--- a/pango/pangocoretext-fontmap.c
+++ b/pango/pangocoretext-fontmap.c
@@ -110,8 +110,8 @@ typedef struct
     PangoWeight pango_weight;
 } PangoCTWeight;
 
-const float ct_weight_min = -0.7f;
-const float ct_weight_max = 0.8f;
+#define ct_weight_min -0.7f
+#define ct_weight_max  0.8f
 
 /* This map is based on empirical data from analyzing a large collection of
  * fonts and comparing the opentype value with the value that OSX returns.