The vbroadcastsi256 intrinsic does not exactly resemble the GCC
builtin. The GCC builtin expects the arguments to be passed by val,
whereas the LLVM intrinsic expects a pointer instead.

This is related to PR 16581 and rdar:14747994.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@188608 91177308-0d34-0410-b5e6-96231b3b80d8