L1Ext_do
Invoke a method with a supercall.
The first operand is an index into the current code's literals, which specifies a method that contains a collection of method definition that might be invoked.
The second operand specifies a literal which is the expected return type of the end. When the invoked method eventually returns, the proposed return value is checked against the pushed type, and if it agrees then this stack entry it is replaced by the returned value. If it disagrees, a runtime exception is thrown instead.
The third operand specifies a literal tuple type. The type union of this and the runtime type of the tuple of arguments is computed and used for method lookup.