[Refactoring] Add findGotoTarget to share common code
[Refactoring] Return NULL from WithStatement::interpret()
[Refactoring] Remove Statement::interpret()
[Refactoring] Remove Expression::interpret()
[Refactoring] Handle NULL Expression or Statement in interpret() call
Add test case to cover version.c.
Merge pull request #4170 from 9rnsr/refactor_ctfe

[Refactoring] Remove interpret member function from Expression and Statement
fix misleading deprecation messages
Merge pull request #4173 from WalterBright/errordep

fix misleading deprecation messages
Print debug/version level instead of __anonymous in error messages.

When integer debug/version levels are used, ident is not defined,
causing Dsymbol::toChars() to print "__anonymous", which is unhelpful.
Instead, it should return the debug/version level being set as an
integer.
Merge pull request #4171 from quickfur/issue13786_version

Issue 13786: Add test case to cover version.c.