If we want to emit things in enum order, use getInstructionsByEnumValue to

If we want to emit things in enum order, use getInstructionsByEnumValue to
get the order, don't compute it ourselves.

Don't emit stuff like (14<<0), emit 14 instead.

Don't attempt to get target properties for builtin instructions.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@25672 91177308-0d34-0410-b5e6-96231b3b80d8