tools: update tooling to work with new macOS CLI …

Using High Sierra and `xcode-select --install` without installing full
Xcode, our build tooling breaks due to faulty regular expressions.

Update the `configure` script in our project root directory to handle
multi-digit version numbers.

`tools/gyp` and `deps/npm/node_modules/node-gyp` still need to be
updated for a complete fix.

PR-URL: https://github.com/nodejs/node/pull/21173


Reviewed-By: Richard Lau <riclau@uk.ibm.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Refael Ackermann <refack@gmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>