[clang-tools-extra] [clang-tidy] Add bugprone-move-shared-pointer-contents check. (PR #67467)

[via cfe-commits]

pizzud wrote:

> Suppose this check should be silent for a shared_ptr with use_count() == 1. Is it possible to change implementation in order to following this way?

Wouldn't that be a runtime check, and thus not something clang-tidy can do without significant data flow analysis effort?

Separately, I finally noticed the failing unit tests on Windows and will start investigating, though I don't have a Windows box so it might be tricky.

https://github.com/llvm/llvm-project/pull/67467