Fixes disassembler crashes on 2013 Haswell RTM instructions.

rdar://13318048


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@176828 91177308-0d34-0410-b5e6-96231b3b80d8
Fix a crasher newly introduced in r176659/r176649, where fast-isel tries to
lower an expect intrinsic that is a constant expression.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@176830 91177308-0d34-0410-b5e6-96231b3b80d8