fix Issue 9739 - DMD not considering ctor with default args as default ctor
Stop using `trySemantic` for detecting base class default ctor
fix Issue 9865 - Crash on bogus import / circular reference
Merge pull request #1835 from 9rnsr/fix9865

[REG2.062] Issue 9865 - Crash on bogus import / circular reference
Merge pull request #1833 from 9rnsr/fix9739

[REG2.063a] Issue 9739 - DMD not considering ctor with default args as default ctor