getDirContents001 hp2ps testing fix

This tweaks the getDirContents001 testcase to ignore the .ps and .aux files
that might be generated by hp2ps if testing of hp2ps via GhostScript is 
enabled. Please include in the 6.6 branch as well as HEAD.

testsuite/tests/ghc-regress/lib/Directory/getDirContents001.hs

@@ -9,3 +9,5 @@ ok name = "getDirContents" `isPrefixOf` name
 	  && not ("bak" `isSuffixOf` name)
 	  && not ("prof" `isSuffixOf` name)
 	  && not ("hp" `isSuffixOf` name)
+          && not ("ps" `isSuffixOf` name)
+          && not ("aux" `isSuffixOf` name)