Updating the perl-5.10 expression to support the bootstrapping stdenv better

- I still have not understood why it worked without this fix before, and I think
this has been triggered by the gcc-4.4, but I have not investigated this much. I
went with the trivial fix.

Adding a glibc-2.10.1 expression, because the glibc-2.11 still does not have
a ports release, so it cannot be used in arm. I'm using it only in native
compilation by now.

Making the default glibc to be 2.10 instead of 2.11 in armv5tel-linux.


svn path=/nixpkgs/branches/stdenv-updates/; revision=18688

pkgs/development/interpreters/perl-5.10/default.nix

@@ -57,7 +57,8 @@ stdenv.mkDerivation {
       ${if stdenv.system == "armv5tel-linux" then "-Dldflags=\"-lm -lrt\"" else ""};
     '';
 
-  preBuild = if (stdenv.gcc.nativeTools) then preBuildNative else preBuildNoNative;
+  preBuild = if (stdenv ? gcc && stdenv.gcc.nativeTools) then
+    preBuildNative else preBuildNoNative;
 
   setupHook = ./setup-hook.sh;
 }