Add pstack, a wrapper script for gdb. Used to be part of gdb.

pkgs/development/tools/misc/gdb/pstack.nix

@@ -0,0 +1,11 @@
+{ stdenv, gdb }:
+stdenv.mkDerivation {
+  name = "pstack-20120823";
+  buildCommand = ''
+    mkdir -p $out/bin
+    cat > $out/bin/pstack <<EOF
+    ${gdb}/bin/gdb -ex "set pagination 0" -ex "thread apply all bt" --batch -p \$1
+    EOF
+    chmod a+x $out/bin/pstack
+  '';
+}