Revert "Bitcode: ArrayRef-ize EmitRecordWithAbbrev(), NFC"

This reverts commit r247107.  Turns out clang calls these functions
directly, and `ArrayRef<T>` doesn't have a working implicit conversion
from `SmallVector<T>`.

http://lab.llvm.org:8080/green/job/clang-stage1-cmake-RA-incremental_build/14247

llvm-svn: 247108