chrootsetup_*: make sure pull_in_lib libraries have +/-x

chrootsetup_*: make sure pull_in_lib libraries have +/-x

When pulling in libraries into the chroot, do make sure that they
either end up with 0755 or 0644 depending on whether or not the
result of `test -x` thinks they're executable.

Whether or not a shared library file has +x or not seems to vary
wildly with apparently no obvious rhyme or reason to it.

When running as root to set up the chroot, the `test -x`
utility will conveniently return a "true" result if *any* of
the executable bits are set and a "false" result otherwise.

Propagate the result of the `test -x` check to all the executable
bits to make sure the library installed in the chroot is consistent
with regards to whether or not it's actually "executable".

Signed-off-by: Kyle J. McKay <mackyle@gmail.com>