bash: use default PATH in FHS environments

If bash is executed within an environment where PATH is not set, it uses
the DEFAULT_PATH_VALUE compiled into bash to set PATH. In nixpkgs we set
this to /no-such-path by default. This makes sense in a nixpkgs/NixOS
environment since paths like /bin or /usr/bin should not be used.
However, when bash is used inside an FHS environment, this produces
results that differ from distributions which follow the FHS standard.

Before this change:
$ steam-run env -i /bin/bash -c 'echo $PATH'
/no-such-path

After this change:
$ steam-run env -i /bin/bash -c 'echo $PATH'
/usr/local/bin:/usr/local/sbin:/usr/bin:/usr/sbin:/bin:/sbin:.

0 files changed, 0 insertions, 0 deletions