/usr/lib/gcc/ is in gcj-4.9-jdk 4.9.3-13ubuntu2.
This file is owned by root:root, with mode 0o755.
..
/usr/lib/gcc/x86_64-linux-gnu/
/usr/lib/gcc/x86_64-linux-gnu/4.9/
/usr/lib/gcc/x86_64-linux-gnu/4.9/include/
/usr/lib/gcc/x86_64-linux-gnu/4.9/include/jawt_md.h
/usr/lib/gcc/x86_64-linux-gnu/4.9/include/jni.h
/usr/lib/gcc/x86_64-linux-gnu/4.9/include/jni_md.h
/usr/lib/gcc/x86_64-linux-gnu/4.9/include/jawt.h
/usr/lib/gcc/x86_64-linux-gnu/4.9/include/gcj/
/usr/lib/gcc/x86_64-linux-gnu/4.9/include/gcj/libgcj-config.h
/usr/lib/gcc/x86_64-linux-gnu/4.9/include/jvmpi.h
/usr/lib/gcc/x86_64-linux-gnu/4.9/libgcj.spec
/usr/lib/gcc/x86_64-linux-gnu/4.9/libgcj_bc.so
/usr/lib/gcc/x86_64-linux-gnu/4.9/libgcj.so
/usr/lib/gcc/x86_64-linux-gnu/4.9/libgcj-tools.so
/usr/lib/gcc/x86_64-linux-gnu/4.9/libgij.so