Implement CALLMETHOD, SH_STRUCTREF and PUSHSTRUCTPAGE instructions.
Constructors are a bit tricky since SH_LOCALCREATE has to implicitly
call an arbitrary number of functions before it returns (just changing
the instruction pointer only allows for calling a single function).
To get around this, there is now a vm_call() function which is used to
call a function synchronously, before returning from the current
instruction.
Methods are implemented as functions, except that they get a struct page
as local variable -1.
Destructors are still not implemented.
Nunuhara Cabbage