coreutils-prefixed: Fix build since the single-binary changes

With the symlinked build it's only renaming 'coreutils' to
'gcoreutils' and leaving all the actual command symlinks alone.

Instead of custom renaming scripts, let's use --program-prefix
from the autotools kitchen sink. This has the nice(?) bonus that
the manpages also get prefixed with 'g' now.

The build system refuses to enable both single-binary build and
--program-prefix - but the symlink-based single-binary build couldn't
possibly work either (as it will be looking at "$0" for which command
to execute).

pkgs/tools/misc/coreutils/default.nix

@@ -39,7 +39,8 @@ let
     configureFlags =
       optional (singleBinary != false)
         ("--enable-single-binary" + optionalString (isString singleBinary) "=${singleBinary}")
-      ++ optional stdenv.isSunOS "ac_cv_func_inotify_init=no";
+      ++ optional stdenv.isSunOS "ac_cv_func_inotify_init=no"
+      ++ optional withPrefix "--program-prefix=g";
 
     buildInputs = [ gmp ]
       ++ optional aclSupport acl
@@ -89,14 +90,7 @@ let
 
     makeFlags = optionalString stdenv.isDarwin "CFLAGS=-D_FORTIFY_SOURCE=0";
 
-    # e.g. ls -> gls; grep -> ggrep
+    postFixup = ""; # FIXME: remove on next mass rebuild
-    postFixup = optionalString withPrefix
-      ''
-        (
-          cd "$out/bin"
-          find * -type f -executable -exec mv {} g{} \;
-        )
-      '';
 
     meta = {
       homepage = http://www.gnu.org/software/coreutils/;

pkgs/top-level/all-packages.nix

@@ -1286,7 +1286,7 @@ in
     aclSupport = stdenv.isLinux;
   };
 
-  coreutils-prefixed = coreutils.override { withPrefix = true; };
+  coreutils-prefixed = coreutils.override { withPrefix = true; singleBinary = false; };
 
   corkscrew = callPackage ../tools/networking/corkscrew { };