Implemented support for building host binaries to test kernel features

Makefile

@@ -60,9 +60,10 @@ $(BUILD_DIR)/%.o: %.c
 	@$(CC) $< -o $@ -c $(CFLAGS) $(ARCH_CFLAGS)
 
 clean:
-	@printf "    \033[1;93mRM\033[0m     Deleting build artefacts.\n"
+	@printf "    \033[1;93mRM\033[0m     Deleting kernel build artefacts.\n"
 	@rm -rf $(BUILD_DIR)
 
+	@$(MAKE) -C sandbox clean
 
 all: $(BUILD_DIR)/$(KERNEL_EXEC)
 
@@ -73,10 +74,13 @@ $(BUILD_DIR)/compile_commands.json:
 
 	@./tools/make/generate_compile_commands.py
 
+sandbox:
+	@$(MAKE) -C sandbox
+
 compile-db: $(BUILD_DIR)/compile_commands.json
 
 include arch/$(ARCH)/extra.mk
 
-.PHONY: all compile-db
+.PHONY: all compile-db sandbox
 
 .INTERMEDIATE: $(ARCH_TEMP_FILES)