Respect environment CPPFLAGS when we run ./configure so we can inject
random -D things without having to set CFLAGS/ASFLAGS

---
 Makeconfig |    1 +
 1 file changed, 1 insertion(+)

--- a/Makeconfig
+++ b/Makeconfig
@@ -668,6 +668,7 @@
 	   $(foreach lib,$(libof-$(basename $(@F))) \
 			 $(libof-$(<F)) $(libof-$(@F)),$(CPPFLAGS-$(lib))) \
 	   $(CPPFLAGS-$(<F)) $(CPPFLAGS-$(@F)) $(CPPFLAGS-$(basename $(@F)))
+CPPFLAGS += $(CPPFLAGS-config)
 override CFLAGS	= -std=gnu99 $(gnu89-inline-CFLAGS) $(config-extra-cflags) \
 		  $(filter-out %frame-pointer,$(+cflags)) $(+gccwarn-c) \
 		  $(sysdep-CFLAGS) $(CFLAGS-$(suffix $@)) $(CFLAGS-$(<F)) \