8154430: Imported modules rebuilt on second run when nothing has changed

Reviewed-by: alanb, tbell

make/CompileJavaModules.gmk

@@ -542,8 +542,9 @@ endif
 ifneq ($(wildcard $(IMPORT_MODULES_CLASSES)/$(MODULE)), )
   $(JDK_OUTPUTDIR)/modules/$(MODULE)/_imported.marker: \
       $(call CacheFind, $(IMPORT_MODULES_CLASSES)/$(MODULE))
-	$(RM) -r $(@D)
-	$(MKDIR) -p $(@D)
+	$(call MakeDir, $(@D))
+        # Do not delete marker and build meta data files
+	$(RM) -r $(filter-out $(@D)/_%, $(wildcard $(@D)/*))
 	$(CP) -R $(IMPORT_MODULES_CLASSES)/$(MODULE)/* $(@D)/
 	$(TOUCH) $@