This class is a container for a list of Instruction objects. Instructions can
be appended, inserted, moved, deleted, etc.. Instructions are being
wrapped into InstructionHandles objects that
are returned upon append/insert operations. They give the user
(read only) access to the list structure, such that it can be traversed and
manipulated in a controlled way.
A list is finally dumped to a byte code array with getByteCode.