Hi! I found and confirmed(with great certainty) 20 issues in LLVM code using static analisys tool. I want create issue on github what is the best way to do this? Is it one mega issue or divided into a dozen separate or one argerator with subissues?
It’s hard to say without seeing the issues, really. If they’re fairly similar/related, one issue is probably best.
I’d say start with filing one issue for all the findings, and folks can decide later if it makes sense to split it up.
But, depending on the issues you’ve found, is there a chance you could send a PR/PRs with fixes instead?
I’m still new to open source contributions. What’s the best approach if I try this variant? There are (potential) bugs in various places and LLVM subsystems. Would it be better to make one PR or several? 20 PRs just seems like too many but combining unrelated changes into one PR also looks bad 
Again, it depends on the nature of the issues/fixes, which we don’t know anything about yet 
If it’s fixing 20 instances of the same kind of problem across different parts of the codebase, a single PR seems fine to me.