[llvm] Added const reference for params wth size >= 16 bytes (PR #125074)

[Herman Semenoff via llvm-commits]

GermanAizek wrote:

> This PR needs breaking up into independent ones for easier review.
> 
> Also, I'm pretty sure `MemoryBufferRef` is intended for passing by value (note the `Ref` part of the name). It's just a pair of pointers... 16 bytes is too small. By that logic, `std::string_view` should be passed by `const &`, at least on Windows, but presumably for others too.

I can split this PR into different branches with others PR, and I also analyzed all structures and classes as parameters under Linux, if there is changing size from OS, more code reviewers (Windows, MacOS, BSD) are needed.

https://github.com/llvm/llvm-project/pull/125074