[llvm] [DevPolicy] Add guidelines for fuzzer-generated issue reports (PR #112372)

[Shafik Yaghmour via llvm-commits]

shafik wrote:

> @shafik I think I've mostly addressed your notes (the two paragraphs after the label mention), please check whether that looks good.

Much better, thank you!

https://github.com/llvm/llvm-project/pull/112372