tools: do not build addons during compilation

The current makefile runs both `cctest` and `build-addons` in parallel
under the assumption that both rely on `all`. Unfortunately
`build-addons` does not rely on all, and there is an edge case where
by it is possible to call `build-addons` while compilation is still
happening.

This patch takes the simplest route by forcing `build-addons` and
`cctest` to run in sequence like the other test targets. This ensures
that `build-addons` will never be run during compilation.

It would be possible to modify `build-addons` to rely on `all` but it
would be a much more aggressive change to the MAKEFILE for a fairly
minor perf bump, as cctest is so fast.

PR-URL: https://github.com/nodejs/node/pull/6723


Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>