interpreter handling for varargs to remove need for looking at Node (#32791)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/32791
When a registered operator has varags (ends with ... in its schema),
the interpreter now appends the number of arguments to the top of
the stack before invoking the operator. This allows the removal of more
uses of Node* in the interpreter.
This PR also then cleans up the constructors for Operator to make
it more likely someone chooses the correct one. After making these ops:
```
USES NODE: prim::TupleUnpack(...) -> (...)
USES NODE: prim::TupleSlice(...) -> (...)
USES NODE: prim::TupleConstruct(...) -> (...)
USES NODE: prim::ListUnpack(...) -> (...)
USES NODE: prim::ListConstruct(...) -> (...)
USES NODE: prim::DictConstruct(...) -> (...)
USES NODE: prim::Constant() -> (...)
USES NODE: prim::isinstance(...) -> (...)
USES NODE: prim::CreateObject(...) -> (...)
USES NODE: prim::fork(...) -> (...)
USES NODE: aten::warn(str message, *, int stacklevel=2) -> () # need stack level information, so ideally in interpreter so it can look at the stack
```
Into interpreter primitives, we can remove all but two constructors for operators:
one that is (schema_string, operation), and one that is (symbol, op_creator) for
the remaining weird primitives.
Test Plan: Imported from OSS
Differential Revision: D19673158
Pulled By: zdevito
fbshipit-source-id: 95442a001538a6f53c1db4a210f8557ef118de66
