[clang] [llvm] [sancov] Introduce optional callback for stack-depth tracking (PR #138323)

[Kees Cook via cfe-commits]

kees wrote:

> ⚠️ C/C++ code formatter, clang-format found issues in your code. ⚠️
> 
> You can test this locally with the following command:
> View the diff from clang-format here.

Whoops, yes, I've fixed these now.

https://github.com/llvm/llvm-project/pull/138323