[HB] Use nil unicode funcs in nil face

src/hb-unicode.c

diff --git a/src/hb-unicode.c b/src/hb-unicode.c
index 47c0396..91da492 100644
--- a/src/hb-unicode.c
+++ b/src/hb-unicode.c
@@ -38,7 +38,7 @@
 static unsigned int hb_unicode_get_combining_class_nil (hb_codepoint_t unicode) { return 0; }
 static unsigned int hb_unicode_get_eastasian_width_nil (hb_codepoint_t unicode) { return 1; }
 
-static hb_unicode_funcs_t _hb_unicode_funcs_nil = {
+hb_unicode_funcs_t _hb_unicode_funcs_nil = {
   HB_REFERENCE_COUNT_INVALID, /* ref_count */
 
   hb_unicode_get_general_category_nil,