Refactoring the whole package related to iterators to increase the stability of dynamic shapes

[hikettei]

Changes

• [BugFix] view with step=-1 wasn't working well: (!view tensor (list 2 3 -1))

  • we have added the vm/iterator package dedicated to calculate offsets considered dynamic shapes.

• [Refactor] Integrated do-compiled-loop and call-with-view

• [Refactor] view.lisp is integrated to vm/iterator

• [Enhancement] JITCPUBackend with dynamic shapes

• Increased the safety of dynamic shapes, especially when combined with multi dimensional offsets

• [Enhancement] When creating a tensor, broadcastable axes can be inserted directly:

  
  CL-WAFFE2-REPL> (proceed
       (!add (ax+b `(3 3) 0 0)
             (ax+b `(~ 3) 1 0)))

{CPUTENSOR[float] :shape (3 3) :id TID855 :vec-state [computed] ((0.0 1.0 2.0) (0.0 1.0 2.0) (0.0 1.0 2.0)) :facet :input :belongs-to :memory-pool :requires-grad NIL :backward <Node: PROCEEDNODE-T (A[~] -> A[~])>}