[RFC] Avoid invalid parameter warnings in C runtime function for mingw builtr GDB

[Eli Zaretskii]

> From: "Pierre Muller" <pierre.muller@ics-cnrs.unistra.fr>
> Cc: <gdb-patches@sourceware.org>
> Date: Tue, 13 Aug 2013 11:13:49 +0200
> 
> Would that be correct?
> 
> #if O_CLOEXEC
>   static int fopen_e_ever_failed = 0;
> #else
>   static int fopen_e_ever_failed = 1;
> #endif

Yes, but Tom's suggestion is more elegant.