gnu: base: Add glibc-hurd and hurd-minimal.

* gnu/packages/base.scm (glibc/hurd, glibc/hurd-headers): New variables.
* gnu/packages/hurd.scm (hurd-minimal): New variable.
* gnu/packages/patches/glibc-hurd-extern-inline.patch: New file.
* gnu/packages/patches/libpthread-glibc-preparation.patch: New file.
* gnu-system.am (dist_patch_DATA): Add them.

Co-authored-by: Ludovic Courtès <ludo@gnu.org>
Co-authored-by: Mark H Weaver <mhw@netris.org>

packages: Define '%hurd-systems'.

* guix/packages.scm (%hurd-systems): New variable.

gnu: make-bootstrap: Remove unneeded configure flag from %gcc-static.

With this commit "guix build bootstrap-tarballs --target=i686-pc-gnu" works.

* gnu/packages/make-bootstrap.scm (%gcc-static): Remove unneeded
  --disable-decimal-float.

gnu: hurd: Add flex as an input to mig.

* gnu/packages/hurd (mig): Add flex as an input.

gnu: acl: Fix i686-gnu build.

* gnu/packages/patches/acl-hurd-path-max.patch: New file.
* gnu-system.am (dist_patch_DATA): Add it.

gnu: gcc: Also substitute the dynamic linker name for GNU/Hurd.

* gnu/packages/gcc.scm (gcc-4.7): Also substitute the dynamic linker name
  for GNU (ie. Hurd) systems.

Signed-off-by: Manolis Ragkousis <manolis837@gmail.com>
Co-authored-by: Ludovic Courtès <ludo@gnu.org>

gnu: bootstrap: Add the location of ld.so on GNU/Hurd.

* gnu/packages/bootstrap.scm (glibc-dynamic-linker): Add the dynamic
  linker for i686-gnu and i585-gnu.

Signed-off-by: Manolis Ragkousis <manolis837@gmail.com>

gnu: acl: Remove explicit 'sed' dependency.

* gnu/packages/acl.scm (acl)[native-inputs]: Remove SED, which is
  implicit.

gnu: coreutils: Drop dependency on libcap when cross-compiling.

* gnu/packages/base.scm (coreutils)[inputs]: Drop LIBCAP
  when (%current-target-system) is true.

Build tarballs with deterministic file ordering.

* guix/packages.scm (patch-and-repack)[build],
  gnu/system/install.scm (self-contained-tarball)[build],
  gnu/packages/make-bootstrap.scm (tarball-package),
  gnu/packages/admin.scm (isc-dhcp),
  gnu/packages/video.scm (avidemux): Pass "--sort=name" to 'tar'.

packages: Add 'armhf-linux' to '%hydra-supported-systems'.

* guix/packages.scm (%hydra-supported-systems): Do not remove 'armhf-linux'
  from it.  It is now equal to '%supported-systems'.

gexp: Remove duplicate 'mkdir-p' definition.

* guix/gexp.scm (%mkdir-p-definition): Remove.
  (%utils-module): New variable.
  (imported-files, compiled-modules): Have gexp load %UTILS-MODULE
  instead of using %MKDIR-P-DEFINITION.

gnu: coreutils: Add dependency on libcap.

* gnu/packages/base.scm (coreutils)[inputs]: Add LIBCAP.

gnu: libcap: Update to 2.24.

* gnu/packages/linux.scm (libcap): Update to 2.24.  Fetch the source
  from mirror://kernel.org.

gnu: glibc: Upgrade to 2.22.

* gnu/packages/base.scm (glibc): Upgrade to 2.22.
  (coreutils-light): New variable.
* gnu/packages/commencement.scm (locale-proof-package): New procedure.
  (%boot5-inputs): Add LD-WRAPPER, BINUTILS-FINAL, BASH-FINAL, GNU-MAKE,
  DIFFUTILS, FINDUTILS, COREUTILS-LIGHT (pass through
  'new-libc-package'), and %BOOTSTRAP-COREUTILS&CO (passed through
  'locale-proof-package'.)

utils: Move 'package-name->name+version' to (guix build utils).

* guix/utils.scm (package-name->name+version): Move to...
* guix/build/utils.scm (package-name->name+version): ... here.  New
  procedure.
* guix/build/emacs-build-system.scm (package-name->name+version):
  Remove.

utils: Add 'strip-store-file-name'.

* guix/build/utils.scm (strip-store-file-name): New procedure.
* guix/build/emacs-build-system.scm (store-directory->name-version):
  Remove.  Update callers to use 'strip-store-file-name'.
* gnu/packages/gcc.scm (make-libstdc++-doc)[arguments]: Use
  'strip-store-file-name' instead of 'string-drop'.

gnu: glibc: _PATH_BSHELL refers to our static bash.

* gnu/packages/base.scm (glibc)[arguments]: Change _PATH_BSHELL in
  paths.h to refer to STATIC-BASH.

gnu: glibc: Use 'modify-phases'.

* gnu/packages/base.scm (glibc)[arguments]: Use 'modify-phases' instead
  of 'alist-cons-before'.

build-system/gnu: Use monotic time to measure elapsed time.

* guix/build/gnu-build-system.scm (gnu-build)[elapsed-time]: New
  procedure.
  Use it, and use (current-time time-monotonic) instead
  of (gettimeofday).  Show one digit after the comma for the elapsed
  time.