Clean up the clean, distclean makefile stuff

Makefile

@@ -40,7 +40,7 @@ test/echo.o: test/echo.c test/echo.h
 	$(CC) $(CFLAGS) -c test/echo.c -o test/echo.o
 
 
-.PHONY: clean distclean test benchmark
+.PHONY: clean clean-platform distclean distclean-platform test benchmark
 
 
 test: test/run-tests
@@ -49,5 +49,8 @@ test: test/run-tests
 bench: test/run-benchmarks
 	test/run-benchmarks
 
-clean:
+clean: clean-platform
+	$(RM) -f *.o *.a test/run-tests$(E) test/run-benchmarks$(E)
+
+distclean: distclean-platform
 	$(RM) -f *.o *.a test/run-tests$(E) test/run-benchmarks$(E)

config-mingw.mk

@@ -39,5 +39,6 @@ oio.a: oio-win.o
 oio-win.o: oio-win.c oio.h oio-win.h
 	$(CC) $(CFLAGS) -c oio-win.c -o oio-win.o
 
-distclean:
-	$(RM) -f *.o *.a
+distclean-platform:
+clean-platform:
+	;

config-unix.mk

@@ -42,6 +42,8 @@ ev/ev.o: ev/config.h ev/ev.c
 ev/config.h:
 	cd ev && ./configure
 
-distclean:
-	$(RM) -f *.o *.a
+clean-platform:
 	$(MAKE) -C ev clean
+
+distclean-platform:
+	$(MAKE) -C ev distclean