[PATCH] Expr::IgnoreImpCasts should also ignore CXXConstructorCalls for implicit copy constructor calls

[Jordan Rose]

  I'm not so sure about this. Apart from not actually skipping all implicit copy constructors (it won't skip the one below), it seems like some clients might need to handle some of the other implicitly-inserted AST nodes.

  ```Foo f = Foo()```

  I think you want `IgnoreImplicit()`, which already exists.

http://llvm-reviews.chandlerc.com/D720