/usr/libx32/libobjc_gc.so.4 is in libx32objc4 6.3.0-18+deb9u1.
This file is owned by root:root, with mode 0o777.
It is a symlink to /usr/libx32/libobjc_gc.so.4.0.0
/usr/libx32/libobjc_gc.so.4.0.0