code: def apply_ir_heuristics(irs, node):
      
  
      irs = integrate_value_gas(irs)
  
      irs = propagate_type_and_convert_call(irs, node)
      irs = remove_unused(irs)
      find_references_origin(irs)
  
  
      return irs
docs: Apply a set of heuristic to improve slithIR