Add llvm_unreachables() for [ASZ]ExtUpper to X86FastISel.cpp to appease the buildbots.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218452 91177308-0d34-0410-b5e6-96231b3b80d8
Add missing attributes !cmp.[eq,gt,gtu] instructions.

These instructions do not indicate they are extendable or the
number of bits in the extendable operand.  Rename to match
architected names.  Add a testcase for the intrinsics.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218453 91177308-0d34-0410-b5e6-96231b3b80d8