add unittests for union and nested structs and classes
Merge pull request #4196 from rainers/addtests_pointerBitmap

add more unittests for __traits(getPointerBitmap)
remove old object.AssociativeArray artefacts
Merge pull request #4198 from IgorStepanov/old-object.AssociativeArray-artefacts

[trivial] remove old object.AssociativeArray artefacts
add -scope switch
Merge pull request #4197 from WalterBright/scopeswitch

DIP69: add -scope switch