Attempt to fix TRT build after library merge (#21775)
Summary:
After fixing https://github.com/pytorch/pytorch/issues/20774 the TRT build was broken
Because of missing annotations, pybind_state_gpu.so was missing symbols, but pybind_state.so did not. It caused a weird combination when trying to import pybind_state_gpu first left system in semi-initialized state and lead to sigsev.
Minimal repro:
```
>>> import ctypes
>>> ctypes.CDLL('/var/lib/jenkins/.local/lib/python2.7/site-packages/caffe2/python/caffe2_pybind11_state_gpu.so')
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
File "/usr/lib/python2.7/ctypes/__init__.py", line 362, in __init__
self._handle = _dlopen(self._name, mode)
OSError: /var/lib/jenkins/.local/lib/python2.7/site-packages/caffe2/python/caffe2_pybind11_state_gpu.so: undefined symbol: _ZN6caffe219TensorRTTransformer9TransformEPNS_9WorkspaceEPNS_6NetDefERKSt13unordered_mapINSt7__cxx1112basic_stringIcSt11char_traitsIcESaIcEEENS_11TensorShapeESt4hashISB_ESt8equal_toISB_ESaISt4pairIKSB_SC_EEE
>>> ctypes.CDLL('/var/lib/jenkins/.local/lib/python2.7/site-packages/caffe2/python/caffe2_pybind11_state.so')
Segmentation fault (core dumped)
```
Too lazy to repro locally, let's see if CI passes
Pull Request resolved: https://github.com/pytorch/pytorch/pull/21775
Differential Revision: D15829605
Pulled By: dzhulgakov
fbshipit-source-id: 1adb2bde56b0cd68f84cfca67bc050adcf787cd9
