/usr/lib/gcc-cross/ is in libobjc-4.9-dev-armhf-cross 4.9.3-13ubuntu2cross1.
This file is owned by root:root, with mode 0o755.
..
/usr/lib/gcc-cross/arm-linux-gnueabihf/
/usr/lib/gcc-cross/arm-linux-gnueabihf/4.9/
/usr/lib/gcc-cross/arm-linux-gnueabihf/4.9/libobjc.a
/usr/lib/gcc-cross/arm-linux-gnueabihf/4.9/libobjc_gc.a
/usr/lib/gcc-cross/arm-linux-gnueabihf/4.9/include/
/usr/lib/gcc-cross/arm-linux-gnueabihf/4.9/include/objc/
/usr/lib/gcc-cross/arm-linux-gnueabihf/4.9/include/objc/objc.h
/usr/lib/gcc-cross/arm-linux-gnueabihf/4.9/include/objc/objc-sync.h
/usr/lib/gcc-cross/arm-linux-gnueabihf/4.9/include/objc/Object.h
/usr/lib/gcc-cross/arm-linux-gnueabihf/4.9/include/objc/runtime.h
/usr/lib/gcc-cross/arm-linux-gnueabihf/4.9/include/objc/objc-exception.h
/usr/lib/gcc-cross/arm-linux-gnueabihf/4.9/include/objc/thr.h
/usr/lib/gcc-cross/arm-linux-gnueabihf/4.9/include/objc/Protocol.h
/usr/lib/gcc-cross/arm-linux-gnueabihf/4.9/include/objc/NXConstStr.h
/usr/lib/gcc-cross/arm-linux-gnueabihf/4.9/include/objc/objc-decls.h
/usr/lib/gcc-cross/arm-linux-gnueabihf/4.9/include/objc/message.h
/usr/lib/gcc-cross/arm-linux-gnueabihf/4.9/libobjc_gc.so
/usr/lib/gcc-cross/arm-linux-gnueabihf/4.9/libobjc.so