update build infrastructure for llvm-16.0.6
Update build infrastructure for LLVM 13.0.0.
Update clang build infrastructure for LLVM 11.1.0.Heavy lifting by mortimer@, thank you so much!
Update build infrastructure for LLVM 10.0.0.ok hackroom@tested by plenty
Update clang build infrastructure for LLVM 8.0.0.
Update clang build infrastructure for LLVM 7.0.1.
Add infrastructure to compile and link LLDB. Inspecting core filesworks, but actually running stuff probably won't.ok kettenis@