[gentoo-musl] Self-hosting Clang-based (libc++, musl libc) stage4

[Jens Staal <staal1978@gmail.com>]

Dear all,

I have made a self-hosting clang-based stage4 that some might want to
play with. LLVM/clang (4) are bootstrapped against libc++ and gcc is
uninstalled (custom crt{begin,end} from ELLCC, see /usr/local/hack/crt)

An update from the last version announced on the gentoo-musl list 1st of
May is that I now have LLVM-patched linux (4.11) sources in there (already
installed and symlinked to /usr/src/linux, default config binaries
installed to /boot)


The stage4 can be downloaded here:
https://mega.nz/#!VrQASApL!F4v7SmS5wkJKBzBigsqptipJYuT94yT3-ObjOWEEG3Y

sha256sum:
6d7d68478ead5c80fa34553cf3fbff2af2916364d1aef0cbdae7147c8761aa81

stuff that might interest the LLVM project:

- the whole system is based on libedit
- some LLVMlinux patch sources:

full patch set from llvmlinux project + extras
https://github.com/staalmannen/linux/tree/llvmlinux

minimal patch set
https://github.com/ramosian-glider/clang-kernel-build

the minimal patch set + some fixes against noisy build
https://github.com/staalmannen/linux/tree/llvmlinux-fresh

The linux 4.11 in /usr/local/portage-clang/sys-kernel/llvm-sources
is patched against the minimal patch set. For later kernel versions I
would most likely go for the llvmlinux-fresh set (alternatively, fixes
are upstream in the kernel or in clang-kernel-build).
Important note: I did not write any of those patches, just applied them.

Some thoughts:
- it would be really cool if an "official" custom crt package for
  llvm/clang could be in portage
- it would be really cool if llvm-sources could be officially supported
  since this would mean that clang actually can be (optionally) used as
  a system compiler with no reliance on gcc (a few years later than freebsd).