This is a followup to 856ae5e. See <http://hydra.gnu.org/build/180506>
for an example of build failure.
* guix/build/gnu-build-system.scm (strip): Add #:archive-strip-flags
parameter. Use it when (ar-file? path).
* guix/build-system/gnu.scm (gnu-build): Add #:archive-strip-flags
parameter and pass it down.
* gnu/packages/commencement.scm (gcc-boot0)[arguments]: Add
#:strip-flags.
* gnu/packages/base.scm (glibc)[arguments]: Likewise.