Add support for getting unit tests from aggregate.
Add unit tests for __traits(getUnitTests).
Add const and better documentation to collectUnitTests.
Merge pull request #2328 from jacob-carlborg/getUnitTests_tests

Unit tests for __traits(getUnitTests)
fix Issue 10651 - Throwing non-Throwable object causes ICE
Merge pull request #2350 from 9rnsr/fix10651

Issue 10651 - Throwing non-Throwable object causes ICE