fix .xz in stdenv bootstrap

Presumably needed due to the last staging merge.
There was some stdenv stage refactoring within, IIRC.

pkgs/tools/text/diffutils/default.nix

@@ -1,4 +1,4 @@
-{ stdenv, fetchurl, coreutils ? null }:
+{ stdenv, fetchurl, xz, coreutils ? null }:
 
 stdenv.mkDerivation rec {
   name = "diffutils-3.3";
@@ -11,7 +11,7 @@ stdenv.mkDerivation rec {
   outputs = [ "out" "info" ];
 
   /* If no explicit coreutils is given, use the one from stdenv. */
-  nativeBuildInputs = [ coreutils ];
+  nativeBuildInputs = [ xz.bin coreutils ];
 
   meta = {
     homepage = http://www.gnu.org/software/diffutils/diffutils.html;

pkgs/tools/text/gawk/default.nix

@@ -1,4 +1,4 @@
-{ stdenv, fetchurl, libsigsegv, readline, interactive ? false }:
+{ stdenv, fetchurl, xz, libsigsegv, readline, interactive ? false }:
 
 let
   inherit (stdenv.lib) optional;
@@ -12,9 +12,9 @@ stdenv.mkDerivation rec {
   };
 
   # When we do build separate interactive version, it makes sense to always include docs.
-  #outputs = stdenv.lib.optionals (!interactive) [ "out" "doc" ]; #ToDo
+  outputs = stdenv.lib.optionals (!interactive) [ "out" "doc" ]; #ToDo
 
-  buildInputs = [ libsigsegv ]
+  buildInputs = [ xz.bin libsigsegv ]
     ++ optional interactive readline;
 
   configureFlags = [ "--with-libsigsegv-prefix=${libsigsegv}" ]

pkgs/tools/text/gnugrep/default.nix

@@ -1,4 +1,4 @@
-{ stdenv, fetchurl, pcre, libiconv ? null }:
+{ stdenv, fetchurl, xz, pcre, libiconv ? null }:
 
 let version = "2.14"; in
 
@@ -12,7 +12,7 @@ stdenv.mkDerivation {
 
   #outputs = [ "out" "doc" ]; ToDo
 
-  buildInputs = [ pcre ]
+  buildInputs = [ pcre xz.bin ]
     ++ stdenv.lib.optional (libiconv != null) libiconv;
 
   patches = [ ./test-localeconv.patch ];