Verify `ninja` on FreeBSD, SunOS, possibly other unixes?

ninja, the only, output of gyp.js needs to be verified on:

• FreeBSD
• SunOS
• Others?...

Suggested way to verify:

1. install node.js on that platform
2. git clone https://github.com/ninja-build/ninja.git && cd ninja && ./configure.py --boostrap && export PATH="cwd:$PATH"
3. git clone https://github.com/indutny/gyp.js && cd gyp.js && npm i && cd ..
4. git clone https://github.com/nodejs/node && cd node
5. ./configure
6. ../gyp.js/bin/gyp -Icommon.gypi -Iconfig.gypi node.gyp -Dtarget_arch=x64 -Dhost_arch=x64
7. ninja -C out/Release
8. Build should succeed, and ./out/Release/node should start
9. Bonus step: python tools/test.py --mode=release -J parallel sequential