fanquake

Added this to `30.0`.

Backported to 29.x in #33225.

> On Linux: > c++ (GCC) 13.2.1 20230801 Just note that you can't assume `c++` is GCC on Linux. There are Linux distros built on LLVM/Clang, like Chimera, but using...

> This also is related: https://codeberg.org/guix/guix/issues/556. Reading the discussion there, it seems like the behaviour is intentional.

There are more improvements we could make here, but we can take, and backport, the (simpler) current change as-is. Anything more will at least require some Guix changes.

Backported to 29.x in #32863.

Closing for now, given the PR was closed. Feel free to discuss further. cc @laanwj @0xB10C

The same kind of quoting is used in multiple places in this file, so if it is incorrect / needs updating, all instances should be changed at the same time.

Please [squash your commits](https://github.com/bitcoin/bitcoin/blob/master/CONTRIBUTING.md#squashing-commits). You can improve the commit message at the same time. i.e "doc: ...."

@Talej Can you rebase this?