Relax static-PE linker object checks

cygwin 1.7

$ iconv --version
iconv (GNU libiconv 1.14)

E:/Develop/haskell/conv.hs :

import Codec.Text.IConv as IConv
import Data.ByteString.Lazy as ByteString

main :: IO ()
main = ByteString.interact (convert "UTF-8" "GBK")        

then

GHCi, version 7.4.1: http://www.haskell.org/ghc/  :? for help
Loading package ghc-prim ... linking ... done.
Loading package integer-gmp ... linking ... done.
Loading package base ... linking ... done.
Prelude> :load "e:/Develop/haskell/conv.hs"
[1 of 1] Compiling Main             ( E:\Develop\haskell\conv.hs, interpreted )
Ok, modules loaded: Main.
*Main> main
Loading package bytestring-0.9.2.1 ... linking ... done.
Loading package iconv-0.4.1.0 ... ghc.exe: panic! (the 'impossible' happened)
  (GHC version 7.4.1 for i386-unknown-mingw32):
	loadArchive "d:/cygwin/lib\\libiconv.a": failed

Please report this as a GHC bug:  http://www.haskell.org/ghc/reportabug

*Main> Leaving GHCi.
<interactive>: Unknown PEi386 section name `.drectve' (while processing: d:/cygwin/lib\libiconv.a)