Allow the build system to build Objective-C sources.
This is needed to move our modified SDL sources under external/qemu/distrib.
As per joeo's request, this change also enables target Objective-C compilation, letting it error at build time.
diff --git a/core/binary.mk b/core/binary.mk
index b64bc81..ddcdc6f 100644
--- a/core/binary.mk
+++ b/core/binary.mk
@@ -212,6 +212,19 @@
endif
###########################################################
+## ObjC: Compile .m files to .o
+###########################################################
+
+objc_sources := $(filter %.m,$(LOCAL_SRC_FILES))
+objc_objects := $(addprefix $(intermediates)/,$(objc_sources:.m=.o))
+
+ifneq ($(strip $(objc_objects)),)
+$(objc_objects): $(intermediates)/%.o: $(TOPDIR)$(LOCAL_PATH)/%.m $(yacc_cpps) $(PRIVATE_ADDITIONAL_DEPENDENCIES)
+ $(transform-$(PRIVATE_HOST)m-to-o)
+-include $(objc_objects:%.o=%.P)
+endif
+
+###########################################################
## AS: Compile .S files to .o.
###########################################################