Enables clang-tidy rule [`misc-use-internal-linkage`](https://clang.llvm.org/extra/clang-tidy/checks/misc/use-internal-linkage.html). This new check was introduced in Clang-Tidy 18 and is available due to recent update of Clang-Tidy 19.
The check marks functions and variables used only in the translation unit as static. Therefore undesired symbols are not leaked into other units, more link time optimisations are possible and the resulting binaries may be smaller.
The detected violations were mostly fixed by using static. In other cases, the symbols were indeed consumed by others files, then their declaring headers were included. Still some declarations were wrong and have been fixed.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/148948
Approved by: https://github.com/Skylion007
There are a number of instrumentation utils which have been added to the profiler toolkit. They are generally small and self contained, often wrapping vendor APIs. (NVTX, ITT)
They don't really interact with the much more expansive machinery of the PyTorch profiler beyond registration / unregistration, minor util sharing, and reusing the profiler base class. Just as in the case of stubs, it makes sense to group them in a dedicated subfolder.
Differential Revision: [D39108649](https://our.internmc.facebook.com/intern/diff/D39108649/)
**NOTE FOR REVIEWERS**: This PR has internal Meta-specific changes or comments, please review them on [Phabricator](https://our.internmc.facebook.com/intern/diff/D39108649/)!
Pull Request resolved: https://github.com/pytorch/pytorch/pull/85511
Approved by: https://github.com/albanD
