Rollup merge of #37159 - cthulhua:readme-mingw-tar, r=alexcrichton

add (missing) tar to list of packages to get under mingw

The distribution targets use tar, but the readme pacman invocation doesn't include the tar package.

Author: Jonathan Turner

README.md

@@ -89,6 +89,7 @@ build.
    $ pacman -S git \
                make \
                diffutils \
+               tar \
                mingw-w64-x86_64-python2 \
                mingw-w64-x86_64-cmake \
                mingw-w64-x86_64-gcc