Makefile: made install target create directories if they dont exist

Makefile

@@ -11,6 +11,7 @@ PREFIX=/usr/local
 CFLAGS=-O3 -s -Wl,-z,noseparate-code,-z,nosectionheader -flto -Lbuild -lyac
 
 build: build_dir cat false tail true
+	rm build/yac.o
 
 clean: build_dir
 	rm -rf build/
@@ -35,6 +36,6 @@ build_dir:
 	mkdir -p build
 
 install: build
-	mkdir -p $(PREFIX)
+	mkdir -p $(PREFIX)/lib $(PREFIX)/bin
 	cp -f build/*.so $(PREFIX)/lib/
 	cp -f build/* $(PREFIX)/bin/