This function deallocates the data structures previously allocated by
SIM_instruction_begin. The instruction can be ended if it is not
yet inserted in the instruction tree or if it is committed
(SIM_instruction_proceed, SIM_instruction_commit). To
remove an inserted instruction use SIM_instruction_squash.
ii is the id of the instruction to deallocate.
Index Thrown if ii is
Sim_IE_OK on success, Sim_IE_Not_Committed if the
instruction is not committed.