Remove preallocation of type ids (#26509)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/26509
We preallocated type ids to align them with ScalarType. At that point, the maximum type id was 10 and we used 11 to specify undefined type id, see https://github.com/pytorch/pytorch/pull/10139.
However, since then, ScalarType got more additions, 11 isn't undefined anymore, and numbers 11-15 have meaning.
caffe2::TypeIdentifier also got its separate additions, 12 and upwards have meaning that differs from ScalarType.
I'm going with the (CI-tested) assumption that caffe2::TypeIdentifier and ScalarType actually don't need to be aligned
and remove the functionality for preallocated type ids. This simplifies our type ids.
ghstack-source-id: 91896918
Test Plan: unit tests
Differential Revision: D17490109
fbshipit-source-id: 800c340d9d3556a99f6e3ffc33af14ad68d7cc59
