/usr/share/doc/libsfgomp1-dbg-armhf-cross is in libsfgomp1-dbg-armhf-cross 4.6.3-1ubuntu5cross1.63.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/share/doc/gcc-4.6-arm-linux-gnueabihf-base
/usr/share/doc/gcc-4.6-arm-linux-gnueabihf-base