I'm really not sure why we were in the first place, it's the linker's job to
convert between BL/BLX as necessary. Even worse, using BLX left Thumb calls
that could be locally resolved completely unencodable since all offsets to BLX
are multiples of 4.
rdar://26182344
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@269101 91177308-0d34-0410-b5e6-96231b3b80d8