Use GetErrorMode if it is available (on Windows Vista and above).

[Peter Rosin]

Hi!

Here's another patch, it makes use of the new function GetErrorMode,
if available, instead of cludging it by calling SetErrorMode twice.
GetErrorMode was introduced with Windows Vista.

This patch does not apply cleanly to a clean git repo, it changes
lines too close to the previous error reporting patch(es), but it
is orthogonal.

Cheers,
Peter

2010-01-02  Peter Rosin  <p...@lysator.liu.se>

        Use GetErrorMode if it is available.
        * libltdl/loaders/loadlibrary.c: (wrap_geterrormode): New
        function that checks if GetErrorMode is supported by the
        system and makes use of it if it is.
        (fallback_geterrormode): New function that is used otherwise
        that implements the old workaround.
        (geterrormode): New function pointer that points at either
        of the above or directly at GetErrorMode.
        (vm_open): Make use of the above.