gnu: grep: Upgrade to 2.20.

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

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: 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'.

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.

Merge branch 'master' into core-updates

gnu: Set proper source location for 'gcc-final'.

* gnu/packages/base.scm (gcc-final)[location]: New field.
  Reported by Andreas Enge <andreas@enge.fr>.

gnu: grep: Upgrade to 2.19.

* gnu/packages/base.scm (grep): Upgrade to 2.19.

Merge branch 'master' into core-updates

gnu: Add GCC 4.9.0.

* gnu/packages/gcc.scm (gcc-4.9): New variable.
* gnu/packages/base.scm (gcc-toolchain-4.9): New variable.

gnu: gmp: Upgrade to 6.0.0a.

* gnu/packages/multiprecision.scm (gmp): Upgrade to 6.0.0a.
* gnu/packages/base.scm (gcc-boot0): Modify symbolic link to point to
    gmp-6.0.0 instead of the non-existing gmp-6.0.0a.

gnu: gcc-final: Add Texinfo as an input.

* gnu/packages/base.scm (gcc-final)[native-inputs]: New field.

gnu: Add 'gcc-toolchain'.

* gnu/packages/base.scm (gcc-toolchain): New procedure.
  (gcc-toolchain-4.8): New variable.

Merge branch 'core-updates'

gnu: glibc: Patch mtrace.pl to avoid retaining a reference to Perl.

* gnu/packages/base.scm (glibc)[argument] <pre-configure phase>: Patch
  malloc/mtrace.pl.

Merge branch 'master' into core-updates