Issue 11618 - Internal Compiler Error

https://d.puremagic.com/issues/show_bug.cgi?id=11618

`copyLiteral` function, which is called from `paintTypeOntoLiteral`, should make shallow copy for `DotVarExp`.

And, for that should use `Expression::copy` rather than `syntaxCopy`, because it will make `e1->type` to `NULL` if expression is `DelegateExp` or `DotVarExp`.

To @donc: Is this legitimate fix?