/usr/lib/gcc-cross/arm-linux-gnueabihf/6/include/ is in libobjc-6-dev-armhf-cross 6.3.0-18cross1.
This file is owned by root:root, with mode 0o755.
..
/usr/lib/gcc-cross/arm-linux-gnueabihf/6/include/objc/
/usr/lib/gcc-cross/arm-linux-gnueabihf/6/include/objc/NXConstStr.h
/usr/lib/gcc-cross/arm-linux-gnueabihf/6/include/objc/Object.h
/usr/lib/gcc-cross/arm-linux-gnueabihf/6/include/objc/Protocol.h
/usr/lib/gcc-cross/arm-linux-gnueabihf/6/include/objc/message.h
/usr/lib/gcc-cross/arm-linux-gnueabihf/6/include/objc/objc-decls.h
/usr/lib/gcc-cross/arm-linux-gnueabihf/6/include/objc/objc-exception.h
/usr/lib/gcc-cross/arm-linux-gnueabihf/6/include/objc/objc-sync.h
/usr/lib/gcc-cross/arm-linux-gnueabihf/6/include/objc/objc.h
/usr/lib/gcc-cross/arm-linux-gnueabihf/6/include/objc/runtime.h
/usr/lib/gcc-cross/arm-linux-gnueabihf/6/include/objc/thr.h