quiet compiler warnings for BLI_array defines, split BLI_array_append into BLI_array_append / BLI_array_append_r, the latter returning the new array location.

source/blender/modifiers/intern/MOD_array.c

@@ -280,6 +280,8 @@ typedef struct IndexMapEntry {
 	short merge_final;
 } IndexMapEntry;
 
+#if 0 /* BMESH_TODO, keep this function??? */
+
 /* indexMap - an array of IndexMap entries
  * oldIndex - the old index to map
  * copyNum - the copy number to map to (original = 0, first copy = 1, etc.)
@@ -305,6 +307,8 @@ static int calc_mapping(IndexMapEntry *indexMap, int oldIndex, int copyNum)
 	}
 }
 
+#endif
+
 static DerivedMesh *arrayModifier_doArray(ArrayModifierData *amd,
 					  Scene *scene, Object *ob, DerivedMesh *dm,
 										  int UNUSED(initFlags))