Unable to build GDB on Windows

[Eli Zaretskii]

> Date: Mon, 28 Sep 2020 18:23:39 +0300
> From: Eli Zaretskii via Gdb <gdb@sourceware.org>
> Cc: gdb@sourceware.org
> 
> > From: Christian Biesinger <cbiesinger@google.com>
> > Date: Mon, 28 Sep 2020 17:17:49 +0200
> > Cc: simon.cook@embecosm.com, Reuben Thomas via Gdb <gdb@sourceware.org>
> > 
> > Hmm that sounds odd, usually the way the Windows SDK works is that
> > this only depends on what you #define, not what you build on
> > (especially _WIN32_WINNT)
> 
> Well, that's true, but how many will use "CPPFLAGS=-D_WIN32_WINNT=..."
> when configuring GDB?  The default is buried somewhere in the MinGW
> headers, and guess what it is?

And actually, in this case the above is not relevant.  Because
getrandom.c bases its logic on the configure-time test that results in
HAVE_LIB_BCRYPT defined to either 1 or zero.  It doesn't look at
_WIN32_WINNT at all.  So yes, the result depends on whether you build
GDB on a system with or without bcrypt.dll.