[SR] Use std::vector::reserve for StaticModule constants (#68834)
Summary:
Pull Request resolved: https://github.com/pytorch/pytorch/pull/68834
This diff uses std::vector::reserve for constructing constants in StaticModule. We can also avoid two extra iterations over all the graph nodes.
This diff should technically improve its performance by a tiny bit.
Test Plan: - [x] buck run //caffe2/benchmarks/static_runtime:static_runtime_cpptest -- -v 1
Reviewed By: mikeiovine
Differential Revision: D32628806
fbshipit-source-id: 99dd2a7a36e86899ca1fe5300f3aa90d30a43726
