[clang] [Clang][Driver] Create crash reproducers for IR inputs (PR #165572)

[Eli Friedman via cfe-commits]

https://github.com/efriedma-quic commented:

Non-LTO IR inputs are in sort of a weird place.  We have handling for them, but we don't really have any rules for exactly what kind of IR inputs we're actually expecting: the format isn't really stable, and we sort of just shove them through whatever pipeline we usually create.  If you do have some workflow, it would be nice to hear about.

We don't want to do this for LTO; the linker is better positioned to generate crash diagnostics in that case.

https://github.com/llvm/llvm-project/pull/165572