[patch 4.5]: Add -municode to mingw targets

[Dave Korn]

Aaron W. LaFramboise wrote:

> 
> i386-pc-windows-mingw
>   is an alias for i386-pc-mingw32
> 
> i386-pc-windows-mingw-w64

  This target triplet has five parts!  Not everyone is even reconciled to
having four-part triplets yet!  Also, isn't mingw-w64 based on x86_64 rather
than i?86?

  Would there be anything particularly wrong with just using two triplets?

i?86-pc-mingw32   - as now
x86_64-pc-mingw64 - Kai's w64 target


    cheers,
      DaveK