de99470d

By: Tom Sydney Kerckhove <syd@cs-syd.eu>

Mutation: cross-package coverage regression test

Add 'sydtest-mutation-example-cross', a library with no test suite of its own,
covered only by 'Example.CrossLibSpec' in the separate
'sydtest-mutation-example-gen' package. The new
'mutation-sydtest-mutation-example-cross' check (libraries = [cross],
tests = [example-gen]) asserts the per-library report attributes that
cross-package coverage and kills the mutations; before the fix it reported them
uncovered. Built green: Killed 36 / Survived 0 / Uncovered 0 / Skipped 0.