Makefile: Use order-only deps for directories (#2728)

* Makefile: Use order-only deps for directories

See https://www.gnu.org/software/make/manual/html_node/Prerequisite-Types.html

* Update Makefile

* Update Makefile

Makefile

@@ -230,13 +230,13 @@ debug-shared: shared
 lib:
  $(MKDIR) lib
 
-lib/libsass.a: lib $(COBJECTS) $(OBJECTS)
+lib/libsass.a: $(COBJECTS) $(OBJECTS) | lib
  $(AR) rcvs $@ $(COBJECTS) $(OBJECTS)
 
-lib/libsass.so: lib $(COBJECTS) $(OBJECTS)
+lib/libsass.so: $(COBJECTS) $(OBJECTS) | lib
  $(CXX) -shared $(LDFLAGS) -o $@ $(COBJECTS) $(OBJECTS) $(LDLIBS)
 
-lib/libsass.dll: lib $(COBJECTS) $(OBJECTS) $(RCOBJECTS)
+lib/libsass.dll: $(COBJECTS) $(OBJECTS) $(RCOBJECTS) | lib
  $(CXX) -shared $(LDFLAGS) -o $@ $(COBJECTS) $(OBJECTS) $(RCOBJECTS) $(LDLIBS) -s -Wl,--subsystem,windows,--out-implib,lib/libsass.a
 
 %.o: %.c
@@ -259,18 +259,17 @@ shared: $(SHAREDLIB)
 $(DESTDIR)$(PREFIX):
  $(MKDIR) $(DESTDIR)$(PREFIX)
 
-$(DESTDIR)$(PREFIX)/lib: $(DESTDIR)$(PREFIX)
+$(DESTDIR)$(PREFIX)/lib: | $(DESTDIR)$(PREFIX)
  $(MKDIR) $(DESTDIR)$(PREFIX)/lib
 
-$(DESTDIR)$(PREFIX)/include: $(DESTDIR)$(PREFIX)
+$(DESTDIR)$(PREFIX)/include: | $(DESTDIR)$(PREFIX)
  $(MKDIR) $(DESTDIR)$(PREFIX)/include
 
-$(DESTDIR)$(PREFIX)/include/sass: $(DESTDIR)$(PREFIX)/include
+$(DESTDIR)$(PREFIX)/include/sass: | $(DESTDIR)$(PREFIX)/include
  $(MKDIR) $(DESTDIR)$(PREFIX)/include/sass
 
 $(DESTDIR)$(PREFIX)/include/%.h: include/%.h \
- $(DESTDIR)$(PREFIX)/include \
- $(DESTDIR)$(PREFIX)/include/sass
+ | $(DESTDIR)$(PREFIX)/include/sass
  $(INSTALL) -v -m0644 "$<" "$@"
 
 install-headers: $(DESTDIR)$(PREFIX)/include/sass.h \
@@ -282,15 +281,15 @@ install-headers: $(DESTDIR)$(PREFIX)/include/sass.h \
  $(DESTDIR)$(PREFIX)/include/sass/functions.h
 
 $(DESTDIR)$(PREFIX)/lib/%.a: lib/%.a \
- $(DESTDIR)$(PREFIX)/lib
+ | $(DESTDIR)$(PREFIX)/lib
  @$(INSTALL) -v -m0755 "$<" "$@"
 
 $(DESTDIR)$(PREFIX)/lib/%.so: lib/%.so \
- $(DESTDIR)$(PREFIX)/lib
+ | $(DESTDIR)$(PREFIX)/lib
  @$(INSTALL) -v -m0755 "$<" "$@"
 
 $(DESTDIR)$(PREFIX)/lib/%.dll: lib/%.dll \
- $(DESTDIR)$(PREFIX)/lib
+ | $(DESTDIR)$(PREFIX)/lib
  @$(INSTALL) -v -m0755 "$<" "$@"
 
 install-static: $(DESTDIR)$(PREFIX)/lib/libsass.a
@@ -320,7 +319,7 @@ test_full: $(SASSC_BIN)
 test_probe: $(SASSC_BIN)
  $(RUBY_BIN) $(SASS_SPEC_PATH)/sass-spec.rb -V 3.5 -c $(SASSC_BIN) --impl libsass --probe-todo $(LOG_FLAGS) $(SASS_SPEC_PATH)/$(SASS_SPEC_SPEC_DIR)
 
-clean-objects: lib
+clean-objects: | lib
  -$(RM) lib/*.a lib/*.so lib/*.dll lib/*.la
  -$(RMDIR) lib
 clean: clean-objects