These new binaries are built with the `--with-lib-path' and
`--with-local-prefix' flags, respectively, as introduced in commit
01d4540.
* distro/packages/bootstrap.scm (%bootstrap-coreutils&co,
%bootstrap-glibc): Update URL.
(%bootstrap-binutils, %bootstrap-gcc): Update URL and hashes.
* build-aux/download.scm (file-name->uri): Update URL.