[3.8 Release] RC2 has been tagged

Here's the status for my builds so far.

clang+llvm-3.8.0-rc2-x86_64-linux-gnu-debian8.tar.xz (sha1sum: 2b546efa5bab19d6711771ef31711d07b4a3f23f)
    All ok
  Cross compiling to various MIPS targets:
    16 out of 23 configs passed
    1 out of the remaining 7 failed a small number of tests with a timeout. I expect these will pass when I re-run them.
    Remaining 6 configs still running...

clang+llvm-3.8.0-rc2-mips-linux-gnu.tar.xz (sha1sum: b46221e1bb54255e9e060f06bb72bb2ba630ff15)
  Failed to run check-all due to tsan'd libc++ build failing
    PR26278 - My fix for this was committed just after the rc2 tag so in order to get some check-all results, I applied those four patches (r25966[1456]) and re-ran check-all.
    PR26369 - Several failures related to the lack of -latomic which is needed for 64-bit atomics.
    PR26476 - One new failure in libc++ (I probably just missed it amongst the others). Apparently std::regex_traits says that '-' doesn't belong to the 'w' class but only on big-endian.
    check-all appears to hang at 99%. I'll look into this.
  LNT (using the clean rc2)
    1 of 3 passed successfully, the other two are still running

clang+llvm-3.8.0-rc2-mipsel-linux-gnu.tar.xz (sha1sum: 9f89cccfdb5cf6a27138b84a631003c4a04f456d)
  Build almost ok. I only have failures related to PR26369.
  LNT just started.

Fedora looks OK, openSUSE not so much, check gets stuck at 90% on x64 but test suite passes OK, on x86 build succeeds but test suite fails saying ‘import spec’ no module found.