add speed benchmark binary for torch jit (#25230)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/25230
Add similar benchmark binary as caffe2 speed benchmark for torch JIT.
Test Plan:
- Test with ResNet-18 torch script model:
```
./speed_benchmark_torch --model=res18.pb --input_dims="1,3,224,224" --input_type=float --print_output=true
./speed_benchmark_torch --model=res18.pb --input_dims="1,3,224,224" --input_type=float --warmup=5 --iter=20
```
- Verified building as desktop/server binary works:
```
BUILD_BINARY=ON python setup.py develop
```
- Verified building as android binary works:
```
./scripts/build_android.sh \
-DBUILD_BINARY=ON \
-DBUILD_CAFFE2_MOBILE=OFF \
-DCMAKE_PREFIX_PATH=$(python -c 'from distutils.sysconfig import get_python_lib; print(get_python_lib())') \
-DPYTHON_EXECUTABLE=$(python -c 'import sys; print(sys.executable)')
```
Differential Revision: D17067216
Pulled By: ljk53
fbshipit-source-id: 0cf4c46f1c90b89bd8dca2a14bb0e5fb70b233a1
