[clang] [compiler-rt] [llvm] [sancov] Add -fsanitize-coverage=trace-args,trace-ret (PR #201410)

[Marco Elver via cfe-commits]

https://github.com/melver commented:

Also consider if there are logical changes that you want committed independently in the LLVM repo. Unfortunately LLVM's Github settings force "squash and merge", which means we need to do "stacked PRs" (https://llvm.org/docs/GitHub.html#stacked-pull-requests).

At the very least, the sets of changes to llvm/, clang/, and compiler-rt/, all need to be split into their own logical PR. 

https://github.com/llvm/llvm-project/pull/201410