PG vs LLVM 12 on seawasp, next round

Hi

Since seawasp's bleeding edge LLVM installation moved to "trunk
20201114 c8f4e06b 12.0.0" ~16 days ago, it has been red.  Further
updates didn't help it and it's now on "trunk 20201127 6ee22ca6
12.0.0".  I wonder if there is something in Fabien's scripting that
needs to be tweaked, perhaps a symlink name or similar.  I don't
follow LLVM development but I found my way to a commit[1] around the
right time that mentions breaking up the OrcJIT library, so *shrug*
maybe that's a clue.

+ERROR:  could not load library

"/home/fabien/pg/build-farm-11/buildroot/HEAD/pgsql.build/tmp_install/home/fabien/pg/build-farm-11/buildroot/HEAD/inst/lib/postgresql/llvmjit.so":
libLLVMOrcJIT.so.12git: cannot open shared object file: No such file
or directory

[1] https://github.com/llvm/llvm-project/commit/1d0676b54c4e3a517719220def96dfdbc26d8048