pytorch

40948a93 - Fix LLVM-12 UB in generate_proposals_op.cc (#66009)

Fix LLVM-12 UB in generate_proposals_op.cc (#66009) Summary: Pull Request resolved: https://github.com/pytorch/pytorch/pull/66009 Fixes ``` test_trace_c10_ops (jit.test_tracer.TestTracer) ... third-party-buck/platform009/build/eigen/include/Eigen/src/Core/Block.h:374:24: runtime error: applying non-zero offset 4 to null pointer #0 0x7f5228f72227 in Eigen::internal::BlockImpl_dense<Eigen::Map<Eigen::Array<float, -1, -1, 1, -1, -1>, 0, Eigen::Stride<0, 0> >, -1, -1, false, true>::BlockImpl_dense(Eigen::Map<Eigen::Array<float, -1, -1, 1, -1, -1>, 0, Eigen::Stride<0, 0> >&, long, long, long, long) third-party-buck/platform009/build/eigen/include/Eigen/src/Core/Block.h:374 #1 0x7f5228f7212c in Eigen::BlockImpl<Eigen::Map<Eigen::Array<float, -1, -1, 1, -1, -1>, 0, Eigen::Stride<0, 0> >, -1, -1, false, Eigen::Dense>::BlockImpl(Eigen::Map<Eigen::Array<float, -1, -1, 1, -1, -1>, 0, Eigen::Stride<0, 0> >&, long, long, long, long) third-party-buck/platform009/build/eigen/include/Eigen/src/Core/Block.h:166 #2 0x7f5228f720dc in Eigen::Block<Eigen::Map<Eigen::Array<float, -1, -1, 1, -1, -1>, 0, Eigen::Stride<0, 0> >, -1, -1, false>::Block(Eigen::Map<Eigen::Array<float, -1, -1, 1, -1, -1>, 0, Eigen::Stride<0, 0> >&, long, long, long, long) third-party-buck/platform009/build/eigen/include/Eigen/src/Core/Block.h:142 #3 0x7f5229b0e059 in Eigen::DenseBase<Eigen::Map<Eigen::Array<float, -1, -1, 1, -1, -1>, 0, Eigen::Stride<0, 0> > >::FixedBlockXpr<internal::get_fixed_value<int>::value, internal::get_fixed_value<long>::value>::Type Eigen::DenseBase<Eigen::Map<Eigen::Array<float, -1, -1, 1, -1, -1>, 0, Eigen::Stride<0, 0> > >::block<int, long>(long, long, int, long) third-party-buck/platform009/build/eigen/include/Eigen/src/Core/../plugins/BlockMethods.h:98 #4 0x7f5229b0c5ca in caffe2::GenerateProposalsOp<caffe2::CPUContext>::RunOnDevice() caffe2/caffe2/operators/generate_proposals_op.cc:348 ``` Also cleans up some data type and const issues around the area. Test Plan: Sandcastle Reviewed By: xush6528 Differential Revision: D31343046 fbshipit-source-id: fd9096c8e47a0aad529c72fd313f64ca98dcb80b