cc1plus.exe of bundled mingw-w64 segfaults

[Shao, Cheng]

Hi folks,

I'm building a Haskell/C++ hybrid project with a recent revision of
ghc on Windows, and noticed that cc1plus.exe always segfaults. The
same code builds fine on AppVeyor however and currently I have no clue
why it ceases to work on my machine. Is anyone else experiencing a
similar problem? I'm not sure if it's worth a trac ticket.

Using cc1plus.exe from a newer version of mingw-w64-x86_64-gcc works
on my machine, but weird linker errors arise when I attempt to use the
newer gcc toolchain to override the bundled one. Is there a way to
manually specify mingw-w64 tarball version/urls when configuring ghc?
I notice there's an "--enable-distro-toolchain" flag, does it work
with building a bindist? Thank you.

Regards,
Shao Cheng