implement tuple constants (#31841)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/31841
Add Tuple Constants to JIT. The constraint here is that all elements of a tuple must themself be insertable as a a constant. Previously tuples were special cased in constant propagation, but now that there are more passes that are inserted constants, such as freezing, we should just have tuples be representable as constants.
Test Plan: Imported from OSS
Differential Revision: D19439514
Pulled By: eellison
fbshipit-source-id: 3810ba08ee349fa5598f4b53ea64525996637b1a
