bug#28601: 26.0.50; configure: error: Emacs does not support 'x86_64-pc-msys' systems.

[Eli Zaretskii]

> From: Noam Postavsky <npostavs@users.sourceforge.net>
> Date: Fri, 13 Oct 2017 12:33:51 -0400
> Cc: Andy Moreton <andrewjmoreton@gmail.com>, 28601@debbugs.gnu.org
> 
> +First we need to switch to the MinGW-w64 environment.  Exit the MSYS2
> +BASH console and run mingw64.exe in the C:\msys64 folder (if it's
> +missing, install it with 'pacman -S msys2-launcher'.  Or for very old
> +installs which have mingw64_shell.bat, use that instead), then cd
> +back to your Emacs source directory, e.g.:

The punctuation inside the parentheses needs fixing (it shouldn't
start a new sentence).  Otherwise, this is fine with me, thanks.