gnu: gcc: Fix cross-compilation of gcc (Canadian cross).

* gnu/packages/gcc.scm (gcc-4.7)[arguments] <#:make-flags>:
  When (%current-target-system) is true, pass the empty list or
  '("CFLAGS=-g0 -O2").

gnu: make-bootstrap: Make sure %gcc-stripped binaries are usable.

* gnu/packages/make-bootstrap.scm (%gcc-stripped):
  When (%current-target-system) is false, run gcc, g++, and cpp with
  --version.

gnu: make-bootstrap: Build %gcc-static with --disable-lto.

* gnu/packages/make-bootstrap.scm (%gcc-static): Pass --disable-lto.

gnu: make-bootstrap: Build libstdc++ in '%gcc-static'.

* gnu/packages/make-bootstrap.scm (%gcc-static): Re-enable C++.

gnu: make-bootstrap: Use single-output GCCs.

* gnu/packages/make-bootstrap.scm (package-with-relocatable-glibc)[native-inputs]:
  Add 'outputs' field for the rewritten GCC.
  (%gcc-stripped): Add 'outputs' field.

gnu: grep: Upgrade to 2.20.

* gnu/packages/base.scm (grep): Upgrade to 2.20.

gnu: gettext: Upgrade to 0.19.1.

* gnu/packages/gettext.scm (gnu-gettext): Upgrade to 0.19.1.

gnu: make-bootstrap: Fix compilation of %gcc-static.

* gnu/packages/make-bootstrap.scm (%gcc-static)[arguments]
  <#:configure-flags>: Add --disable-bootstrap
  --with-stage1-ldflags=-static.
  Remove #:make-flags.

gnu: cross-gcc: Use a single output.

* gnu/packages/cross-base.scm (cross-gcc): Add 'outputs' field.

gnu: coreutils: Remove run-time dependency on Bash.

* gnu/packages/base.scm (coreutils)[arguments] <patch-shell-references>:
  Leave src/split.c unpatched.  Set $SHELL.  Use .../bin/sh and not
  .../bin/bash in tests.

gnu: gcc: Add a "lib" output.

* gnu/packages/gcc.scm (gcc-4.7)[configure-flags]: Add
  --with-gxx-include-dir.
  [outputs]: New field.
  [arguments] <phases>: Adjust to use the "lib" output.  Add
  'substitute*' calls for "libstdc++-v3/python/Makefile.in" and
  "gcc/config.in".
* gnu/packages/base.scm (gcc-boot0) <symlink-libgcc_eh>: Use the "lib"
  output.
  (cross-gcc-wrapper): Add 'outputs' field.
  (glibc-final)[arguments]: Adjust #:allowed-references to list
  '(GCC-BOOT0 "lib").
  (libstdc++): Add 'outputs' field.
  (gcc-final)[arguments]: Add "lib" to #:allowed-references.
* gnu/packages/make-bootstrap.scm (%gcc-static): Add 'outputs' field.

gnu: glibc-final: Remove top-level circular dependency.

This fixes a top-level circular dependency between linux.scm and
base.scm introduced in 2e92375.

* gnu/packages/base.scm (glibc-final): Remove call to
  'package-with-restricted-references', and use an 'arguments' field
  instead.

gnu: libunistring: Work around parallel build issue.

* gnu/packages/libunistring.scm (libunistring)[arguments]: New field.

gnu: gettext: Remove debugging leftover.

* gnu/packages/gettext.scm (gnu-gettext)[source](patches): Remove.

gnu: gcc-final: Make sure the output refers only to libc.

* gnu/packages/base.scm (gcc-final)[arguments]: Add
  #:allowed-references.

gnu: binutils-final: Make sure the output refers only to libc.

* gnu/packages/base.scm (binutils-final)[arguments]: Add
  #:allowed-references.

gnu: glibc-final: Make sure we hold just the right set of references.

* gnu/packages/base.scm (glibc-final): Wrap in
  'package-with-restricted-references'.

build-system/gnu: Add 'package-with-restricted-references'.

* guix/build-system/gnu.scm (package-with-restricted-references): New
  procedure.

gnu: glibc: Make sure the bootstrap libc is not in $CPATH.

This fixes a bug whereby the bootstrap-glibc headers could be picked up
when building libc.so, which could be noticed by the fact that the
.debug files contained references to bootstrap-glibc.

* gnu/packages/base.scm (glibc-final-with-bootstrap-bash)[arguments]:
  Add 'pre-configure' phase.
  [inputs]: Remove 'alist-delete' call.

gnu: Build the final Coreutils before Findutils.

This fixes a bug whereby Findutils' 'updatedb' script would retain a
reference to the bootstrap binaries ('sort', etc.)

* gnu/packages/base.scm (coreutils-final, %boot5-inputs): New variables.
  (%final-inputs): Use them.