Fuzz bug: InternalError: deserialize a non-representable scval

[graydon]

   1: [Diagnostic Event] contract:0000000000000000000000000000000000000000000000000000000000000000, topics:[error, Error(Value, InternalError)], data:["unexpected non-Val-representable ScVal type", 20]

inside a call to deserialize_from_bytes, from this program:

	Expr(
	    deserialize_from_bytes(
	        bytes_push(
	            bytes_pop(
	                serialize_to_bytes(
	                    vec_back(
	                        vec_push_back(
	                            vec_new_or_existing(
	                                0,
	                            ),
	                            sub_Void(
	                                extend_contract_instance_and_code(
	                                    get_current_contract_address,
	                                    get_ledger_version,
	                                    get_ledger_version,
	                                ),
	                            ),
	                        ),
	                    ),
	                ),
	            ),
	            get_ledger_version,
	        ),
	    ),
	)

Probably just a little too quick to treat non-representability as InternalError rather than potentially-user-controlled input.