darwin: Use -fvisibility=hidden to set default symbol visibility

Signed-off-by: Jeremy Huddleston <jeremyhu@apple.com>
diff --git a/configs/darwin b/configs/darwin
index 9d3bbcf..9527f61 100644
--- a/configs/darwin
+++ b/configs/darwin
@@ -25,9 +25,9 @@
 
 ARCH_FLAGS += $(RC_CFLAGS)
 
-CFLAGS =  -ggdb3 -Os -Wall -Wmissing-prototypes -std=c99 -ffast-math -fno-strict-aliasing \
+CFLAGS =  -ggdb3 -Os -Wall -Wmissing-prototypes -std=c99 -ffast-math -fno-strict-aliasing -fvisibility=hidden \
 	-I$(INSTALL_DIR)/include -I$(X11_DIR)/include $(OPT_FLAGS) $(PIC_FLAGS) $(ARCH_FLAGS) $(ASM_FLAGS) $(DEFINES)
-CXXFLAGS =  -ggdb3 -Os -Wall -fno-strict-aliasing \
+CXXFLAGS =  -ggdb3 -Os -Wall -fno-strict-aliasing -fvisibility=hidden \
 	-I$(INSTALL_DIR)/include -I$(X11_DIR)/include $(OPT_FLAGS) $(PIC_FLAGS) $(ARCH_FLAGS) $(ASM_FLAGS) $(DEFINES)
 
 # Library names (actual file names)