afl++ is not compatible with llvm 15

[vanhauser-thc]

A quick test showed that llvm 15 disabled the old pass manager. we have not ported to the new one because it is a lot, really a lot of work.
so heads up - dont upgrade to llvm 15. dunno when we will have time to update all our passes ... :(

[jonathanmetzman]

ACK. I think we are still pinned to llvmorg-14-init-7378-gaee49255

[jonathanmetzman]

I think this has been fixed right?

[vanhauser-thc]

yes, LTO is not possible anymore as they borked custom plugin loading in lld though, but this does not affect oss-fuzz.

[fanquake]

Can this be closed now? My understanding is that afl++ is now compatible with LLVM 18 since #11404.