gh-158380: Fix the stack operand used by JIT dict access guards

[cocolato]

The probable type branches of _GUARD_NOS_DICT_SUBSCRIPT and _GUARD_NOS_DICT_STORE_SUBSCRIPT now check the dict at NOS:

Stack (top on the right):
  Read:  ... mapping, key
  Write: ... value, mapping, key

Before: _GUARD_TYPE     checks type(key)     == expected_type
After:  _GUARD_NOS_TYPE checks type(mapping) == expected_type

Reuse the existing NOS guard by renaming _GUARD_TYPE_ITER to _GUARD_NOS_TYPE, update its iterator call site, and regenerate the affected files fix this issue. Known-type paths still omit the guard.

• Issue: JIT dict access guards check the wrong stack operand #158380