/usr/lib/arm-none-eabi/newlib/thumb/libg.a is in libnewlib-arm-none-eabi 2.4.0.20160527-2.
This file is owned by root:root, with mode 0o644.
It is a symlink to /usr/lib/arm-none-eabi/newlib/thumb/./usr/lib/arm-none-eabi/newlib/thumb/libc.a