pytorch

649dda9f - [jit] Implement DynamicType for TorchScript runtime. (#68136)

[jit] Implement DynamicType for TorchScript runtime. (#68136) Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/68136 DynamicType is an extension to existing server JIT types. Today using normal server types on Edge is a bit problematic because in embedded environments we don't need the full spectrum of types but we still build with these unneeded dependencies. Is it possible to just get rid of unneeded JIT types from Edge builds? It's not easy to do so at this moment. For example, on Edge we don't support Union type, but we have to pull in the dependency of Union type because Optional type is being supported which inherits from Union type, so Union type has to be included in the build. Although we could split Union type and Optional type, it could be argued that the root cause is every time we use anything inheriting from `c10::Type`, we don't have the direct evidence of how much dependency we pull in, because we do virtual calls and we don't know what exactly we're calling with server JIT types. If we don't know, it's highly possible that the linker doesn't know either so it cannot effectively strip unused methods. To address this problem, one option is to implement a separate `DynamicType` which has simpler behavior and doesn't store different types as different symbols in binary but rather raw data (or "tag"). This could increase the binary size by several KBs, so I included several binary size reductions in the same stack, hoping at least we don't regress the binary size. Currently `DynamicType` inherits from `c10::Type` because I want to reduce the migration cost of `DynamicType` by making it interfacing with existing server JIT types. In the future `DynamicType` should be implemented as a separate class without relying on `c10::Type` to make things both simpler and leaner. ghstack-source-id: 146670522 Test Plan: in the next diff. Reviewed By: VitalyFedyunin Differential Revision: D32264615 fbshipit-source-id: 180eb0998a14eacc1d8b28db39870d84fcc17d5b