Add RefineTypes JIT pass for Tuple (#76919)
Consider the following JIT graph, where the type of `%a` and `%b` are out of sync with tuple `%c`.
Before:
```
graph(%a : Float(123), %b : Float(4, 5, 6)):
c : (Tensor, Tensor) = prim::TupleConstruct(%a, %b)
return (%c)
```
After:
```
graph(%a : Float(123), %b : Float(4, 5, 6)):
c : (Float(123), Float(4, 5, 6)) = prim::TupleConstruct(%a, %b)
return (%c)
```
This PR adds a pass `RefineTypes(...)` to update all such instances with the correct type. This is also available via Python by using `torch._C._jit_pass_refine_types(...)`.
A unit test has been added for unnamed tuples, but no test exists for `NamedTuple` (though it was tested manually) since it isn't supported by the parser:
```
RuntimeError:
unknown type specifier:
graph(%a : Float(123), %b : Float(4, 5, 6)):
%c : NamedTuple(Tensor : Tuple, Tensor : Tuple) = prim::TupleConstruct(%a, %b)
~~~~~~~~~~ <--- HERE
return (%c)
```
cc: @ke1337 @antoniojkim @wconstab @eellison
Pull Request resolved: https://github.com/pytorch/pytorch/pull/76919
Approved by: https://github.com/eellison
