[mac] Fix Savannah bug #48417.

Mac OS X linker throws errors when `-exported_symbol_list' input
file includes non-existing symbols.  Reported by Ryan Schmidt.

* builds/exports.mk: Exclude ftmac.h from the headers for apinames
by default.  Include it when ftmac.c would be compiled.

ChangeLog

@@ -1,3 +1,13 @@
+2016-07-07  suzuki toshiya  <mpsuzuki@hiroshima-u.ac.jp>
+
+	[mac] Fix Savannah bug #48417.
+
+	Mac OS X linker throws errors when `-exported_symbol_list' input
+	file includes non-existing symbols.  Reported by Ryan Schmidt.
+
+	* builds/exports.mk: Exclude ftmac.h from the headers for apinames
+	by default.  Include it when ftmac.c would be compiled.
+
 2016-07-06  Werner Lemberg  <wl@gnu.org>
 
 	* src/truetype/ttinterp.c (TInstruction_Function): Removed, unused.

builds/exports.mk

@@ -40,7 +40,11 @@ ifneq ($(EXPORTS_LIST),)
   endif
 
   # The list of public headers we're going to parse.
-  PUBLIC_HEADERS := $(wildcard $(PUBLIC_DIR)/*.h)
+  PUBLIC_HEADERS := $(filter-out $(PUBLIC_DIR)/ftmac.h, \
+                                 $(wildcard $(PUBLIC_DIR)/*.h))
+  ifneq ($(ftmac_c),)
+    PUBLIC_HEADERS += $(PUBLIC_DIR)/ftmac.h
+  endif
 
   # The `apinames' source and executable.  We use $E_BUILD as the host
   # executable suffix, which *includes* the final dot.