Fix typo in patch to fix clang build.
Adjust the set of headers installed with clang to match llvm90. Also
correct the location of the patch.
Reported by: yuri (lack on unwind.h)
Update to a new snapshot.
powerpc64: add configure option to select ELFv2 ABI
In preparation for compiler+ABI change in PowerPC64, this change adds a
configure option to select ELFv2 as default powerpc64 ABI when compiling
llvm-devel.
The new option automatically set when ELFv2 environment is detected
(when PPC_ABI=ELFv2)
Submitted by: Alfredo Dal'Ava Junior
Differential Revision: https://reviews.freebsd.org/D22100