patch applied (cabal): Also check compiling C headers at configure-time

[Duncan Coutts]

Wed Apr 14 23:36:57 PDT 2010  Duncan Coutts <duncan at haskell.org>
  * Also check compiling C headers at configure-time
  So we now both check if the headers can be pre-processed and separately
  if they can be compiled. If it fails the pre-processing check then it
  is usually (but not always) a missing header. If it fails to compile
  then it is definately borked, not missing. Error messages reflect this.

    M ./Distribution/Simple/Configure.hs -41 +61

View patch online:
http://darcs.haskell.org/cgi-bin/darcsweb.cgi?r=cabal;a=darcs_commitdiff;h=20100415063657-adfee-54afa51911596d6c7e1fdb24be7a8fd68c02fcdf.gz