Fixes Issue 9635 - Improve message on missing this diagnostics.
Merge pull request #1721 from AndrejMitrovic/Fix9635

Issue 9635 - Improve message on missing 'this' diagnostics.
Set sc->parent during AggregateDeclaration::semantic2 and semantic3
[Refactoring] isNeedThisScope
Add toAliasFunc call to track correct f->parent
[REG2.063a] fix Issue 9633 - compiles trait wrongly returns true even when object method call actually does not compile

Improve isNeedThisScope