Investigate the cmake crash on attempt to setup parallel build for couchbase-lite-core-windows, need to reduce the build time from 30+ mins down to 15 mins or so

Currently run into cl.exe crash with the following error when running Win32, Win64 and ARM architecture in parallel:

config build.-- The C compiler identification is MSVC 19.0.24215.1
– The CXX compiler identification is MSVC 19.0.24215.1
– Check for working C compiler: C:/Program Files (x86)/Microsoft Visual Studio 14.0/VC/bin/x86_amd64/cl.exe
– Check for working C compiler: C:/Program Files (x86)/Microsoft Visual Studio 14.0/VC/bin/x86_amd64/cl.exe – broken
CMake Error at C:/Program Files/CMake/share/cmake-3.8/Modules/CMakeTestCCompiler.cmake:51 (message):
  The C compiler "C:/Program Files (x86)/Microsoft Visual Studio
  14.0/VC/bin/x86_amd64/cl.exe" is not able to compile a simple test program.

need to run these 3 architectures in parallel to reduce the build time.