[AArch64][GlobalISel] Fix assert fail with unknown intrinsic.

A call may have an intrinsic name but not have a valid intrinsic ID,
for example with llvm.invariant.group.barrier. If so, treat it as a
normal call like FastISel does.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@321662 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed