patch applied (ghc): Fix Windows memory freeing: add a check for fb == NULL; fixes trac #4506

[Ian Lynagh]

Wed Dec  8 07:23:49 PST 2010  Ian Lynagh <igloo at earth.li>
  * Fix Windows memory freeing: add a check for fb == NULL; fixes trac #4506
  Also added a few comments, and a load of code got indented 1 level deeper.

    M ./rts/win32/OSMem.c -40 +51

View patch online:
http://darcs.haskell.org/cgi-bin/darcsweb.cgi?r=ghc;a=darcs_commitdiff;h=20101208152349-3fd76-c048efa0a7c72c6363fc5b6ef83d0bae8f19fac9.gz