zos: add search locations for libnode.x
zos: add search locations for libnode.x

Node.js on z/OS uses shared dll (libnode.so). When linking native
addons, node-gyp needs to find the corresponding libnode.x during
the link step.

PR-URL: https://github.com/nodejs/node-gyp/pull/1451
Reviewed-By: Ben Noordhuis <59bd0a3ff43b32849b319e645d4798d8a5d1e889@bnoordhuis.nl>
Reviewed-By: Refael Ackermann <0604a90ccdde7a0adfa2ff3857349859a7209740@gmail.com>

refack/node-gyp,TooTallNate/node-gyp,refack/node-gyp,refack/node-gyp,TooTallNate/node-gyp,TooTallNate/node-gyp,TooTallNate/node-gyp,refack/node-gyp,TooTallNate/node-gyp,refack/node-gyp