[clang] [llvm] Singleton hack of fixing static initialisation order ficaso (PR #154541)

[Mircea Trofin via cfe-commits]

mtrofin wrote:

> @mtrofin I have tried writing an explanation by editing the PR's first comment. Could you verify if this would explain enough or is it not enough for some reason?

This helps! Some nits:  if you look at other PRs in our repo, we don't do much formatting, i.e. no need for lots of headers and all that. If I may: you could, for example, summarize all of it as `Indirect linking of llvm as a shared library is causing a "free() invalid size abortion". In my case, my project depends on google/clspv which in turn pulls llvm. Note that the issue does not occur when clspv is statically linked`. <- I'm assuming that is the library you're talking about in `When library is all statically linked, this problem did not occur.` 

I'd also use this context in the referenced issue (so it can be stand-alone readable)



https://github.com/llvm/llvm-project/pull/154541