[indic/myanmar] Rename OT_NBSP to OT_PLACEHOLDER

src/hb-ot-shape-complex-myanmar.cc

diff --git a/src/hb-ot-shape-complex-myanmar.cc b/src/hb-ot-shape-complex-myanmar.cc
index 66ca1cf..149a025 100644
--- a/src/hb-ot-shape-complex-myanmar.cc
+++ b/src/hb-ot-shape-complex-myanmar.cc
@@ -134,7 +134,7 @@
   OT_D   = 19, /* Digits except zero */
   OT_D0  = 20, /* Digit zero */
   OT_DB  = OT_N, /* Dot below */
-  OT_GB  = OT_NBSP,
+  OT_GB  = OT_PLACEHOLDER,
   OT_MH  = 21, /* Various consonant medial types */
   OT_MR  = 22, /* Various consonant medial types */
   OT_MW  = 23, /* Various consonant medial types */