In contrast to MSYS2, MSYS1 not only defines REPARSE_DATA_BUFFER in
"ntifs.h" but also in "winnt.h". Luckily, we can distinguish between
MSYS1's and MSYS2's "winnt.h" by looking at the include-guards:
While MSYS1 defines "_WINNT_H", MSYS2 defines "_WINNT_".
Signed-off-by: Sebastian Schuberth <sschuberth@gmail.com>