* gnu/packages/patches/guile-lzlib-hurd64.patch: New file.
* gnu/local.mk (dist_patch_DATA): Register it.
* gnu/packages/guile.scm (guile-lzlib)[arguments]: Use G-expressions. When
building for the 64bit Hurd, or cross-compiling, use it in new
"apply-hurd64-patch" stage.
Change-Id: Id03f71baa80e2f4f967f54037ce7d9f1c5dc4bb6