Fix #1926 by propagating rawness from the primary of a QME to the QME (which then gets propagated to the InvocationExpression. A further fix is necessary because if the result type of a method invocation is a type parameter and the invocation has raw type then the invocation is effectively erased. Finally we only need the type cast to Object when an expression of untrusted type is not already raw.
Add test for #1926
Other .src changed by fix to #1926