message: [Docs] Update Windows build instructions for using WSL and Ubuntu 17.04
  Github-Pull:
  Rebased-From:
diff: @@ -4,10 +4,11 @@ WINDOWS BUILD NOTES
  Below are some notes on how to build Bitcoin Core for Windows.
  Most developers use cross-compilation from Ubuntu to build executables for
  -Windows. This is also used to build the release binaries.
  +Windows. Cross-compilation is also used to build the release binaries.
  -Currently only building on Ubuntu Trusty 14.04 is supported.
  -Other versions are unsupported or known to be broken (e.g. Ubuntu Xenial 16.04).
  +Currently only building on Ubuntu Trusty 14.04 or Ubuntu Zesty 17.04 or later is supported.
  +Building on Ubuntu Xenial 16.04 is known to be broken, see extensive discussion in issue [8732](https://github.com/bitcoin/bitcoin/issues/8732).
  +While it may be possible to do so with work arounds, it's potentially dangerous and not recommended.
  While there are potentially a number of ways to build on Windows (for example using msys / mingw-w64),
  using the Windows Subsystem For Linux is the most straightforward. If you are building with
  @@ -62,6 +63,14 @@ A host toolchain (`build-essential`) is necessary because some dependency
  packages (such as `protobuf`) need to build host utilities that are used in the
  build process.
  +
  +If you're building on Ubuntu 17.04 or later, run these two commands, selecting the 'posix' variant for both,
  +to work around issues with mingw-w64. See issue [8732](https://github.com/bitcoin/bitcoin/issues/8732) for more information.
  +```
  +sudo update-alternatives --config x86_64-w64-mingw32-g++
  +sudo update-alternatives --config x86_64-w64-mingw32-gcc
  +```
  +
  ## Building for 64-bit Windows
  To build executables for Windows 64-bit, install the following dependencies:
  