LLVM-related projects and the steps to a GPL-free runtime

[Joerg Sonnenberger <joerg%britannica.bec.de@localhost>]

Hi all,
as you might have seen, I've been working on LLVM/Clang support in base
and pkgsrc. I would like to continue and actually bring both into the
base system as alternative compiler at least for X86. In the near
future, I want to also completent this with a number of libraries to
replace the GNU library stack: compiler-rt, libc++, libcxxrt and either
libunwind or something functionally equivalent.

There are a number of missing items to get libc++ fully working, but
that can be done incrementally. Clang in base gives easy access to
another set of compiler warnings, normally less optimizer sensitive than
GCC, as well as a modern code base for a static analyzer (to replace
lint).

Due to the highly active upstream, I want to avoid any local
(non-temporary) changes and would request a pre-commit filter for HEAD
for the corresponding parts of src. It is very easy to get upstream
commit access for LLVM-related projects and all patches should be
committed upstream first. If it is really necessary to apply a short
term band aid, it can still go unto the vendor branch.

Joerg