Generate a shared library linked to integration_test_target

[ttreyer]

Summary

Extend our integration test suite by linking a generated shared library to the integration_test_target. This enable us testing and validating that oid handles shared libraries. We can add definitions in the shared library using the keys definitions_shlib and raw_definitions_shlib.

Test plan

There are no tests using the new shlib definitions, yet. However, we can see this PR is not affecting our existing tests:

$ make configure-devel
[...]

$ make test
[...]
100% tests passed, 0 tests failed out of 420

Total Test time (real) =  75.04 sec