Lint missing lints in LintPasses

[llogiq]

If we miss a Lint in the lint_array! of the *LintPass, we will get strange and confusing behavior (like lint warnings + unknown_lint).

This requires walking the call graph and recording any lint symbol on the way. Then checking the get_lints method if all recorded lints are present.

Note that this would be the first lint that is specifically aimed at helping write lints.

[oli-obk]

Make sure to take a Totem with you.

[llogiq]

We don't need to follow the call graph, just identify the reachable functions for any LintPass implementation. The naive set-based algorithm should work nicely.

[mcarton]

Closed by #1207.