[llvm] MC: Store fragment content and fixups out-of-line (PR #146307)

[Alexis Engelke via llvm-commits]

https://github.com/aengelke commented:

Generally LGTM. Thanks a lot for finishing this up!

I'm not too happy about the performance loss, but I still think this is a good direction nonetheless. I have some (unbenchmarked) suggestions for perf improvements, maybe we could evaluate these before merging?

https://github.com/llvm/llvm-project/pull/146307