Perf: Apply more clang-tidy fixups to torch headers (#91445)
Applies so more fixes to headers that may have been missed before for performance optimization.cc @jgong5 @mingfeima @XiaobingSuper @sanchitintel @ashokei @jingxu10 @EikanWang @ezyang since this more in the series of the clang-tidy fixup
This is PR fixes 3 main issues:
1. Use emplacement more in headers
1. Avoid unnecessary copies and use const ref when possible
1. Default any special functions when possible to make them potentially trivial and more readable.
1. There is also one change in this PR that tries to prevent unnecessary math promotion, the rest of these changes are in another PR
Pull Request resolved: https://github.com/pytorch/pytorch/pull/91445
Approved by: https://github.com/ezyang
