remove unnecessary unmarshaling code for the standard-marshal case -
this is handled by CoUnmarshalInterface and CoReleaseMarshalData.

ole32: Add a rough implementation of the free-threaded marshaler MarshalInterface and UnmarshalInterface methods, with test cases.

start of the memory that an embedded pointer is embedded in so that
FC_POINTER conformance works correctly.

Set stubMsg.StackTop after calling the initialise function.