Patches 1-2 are just rebased from the earlier version for clang
3.8, no changes in surrounding code there.
Patch 3 is necessary to fix a regression in assembling standalone
assembly files in 3.9.
Patch 4 makes clang work in MSVC mode with the MSVC SDK for ARM
(to simplify testing of the toolchain in that mode).
Martin Storsjö
feac2f56ba