[PATCH] Conditionally include "<windows.h>" on common/pathstuff.c (and unbreak build on mingw*)

[Yao Qi]

Sergio Durigan Junior <sergiodj@redhat.com> writes:

> Introduced a regression when compiling for mingw*:
>
>   /gdb/common/pathstuff.c: In function 'gdb::unique_xmalloc_ptr<char>
>   gdb_realpath(const char*)':
>   /gdb/common/pathstuff.c:56:14: error: 'MAX_PATH' was not declared in this scope
>        char buf[MAX_PATH];

Fedora-x86_64-w64-mingw32 catches this build failure
https://gdb-build.sergiodj.net/builders/Fedora-x86_64-w64-mingw32/builds/1113/steps/compile%20gdb/logs/stdio
but it doesn't send notification on build failure.  Could you change the
buildbot config to send notification on build failure?  The same as
other builders do.

-- 
Yao (齐尧)