Support for LLVM 11/12/13/14

[lzaoral]

Issue to track changes needed to support LLVM 11, 12, 13 and 14:

tool	11	12	13	14
dg	✅	✅	✅	✅
sbt-slicer	✅	✅	✅	✅
klee	klee/klee#1321 and klee/klee#1330	klee/klee#1389	klee/klee#1431	klee/klee#1477
sbt-instrumentation	✅	✅	✅	✅
llvm2c	✅	✅	✅	✅
sbt-transforms	✅	✅	✅	✅
symbiotic	✅	✅	✅	✅

[lzaoral]

I've updated the issue to include LLVM 13 as well.

[lzaoral]

All PRs to KLEE's upstream have been merged! 🥳

[mchalupa]

Great work! 👍

[lzaoral]

I've updated the issue to include LLVM 14 as well since 14.0.0-rc1 is scheduled for Feb 4 and final release for Mar 15.

[MichalHe]

(probably relevant for this issue:)

The default LLVM (10.0.1) cannot be built anymore with newer compilers (GCC 11+, Clang 12+) due to some changes in library dependencies described here. To be precise, the compilation of LLVM when using build.sh failed on compiling llvm-10.0.1/utils/src/benchmark_register.h. Patching the file to with an extra #include <limits> directive solved the problem. The GCC version used was 11.3.1, Fedora 35.

[lzaoral]

Thanks @MichalHe! Some unmerged (and unreviewed) fixes to the build.sh script are in the symbiotic9.1 branch. Also, you can use the unofficial package for Fedora: https://copr.fedorainfracloud.org/coprs/g/aufover/symbiotic/ (Note that F37 packages are not completely functional at the moment since Symbiotic does not support LLVM 15 yet.)