Don't call PrepareEHLandingPad on non EH pads

This was a minor bug in r249492. Calling PrepareEHLandingPad on a
non-landingpad was a no-op, but it attempted to get the generic pointer
register class, which apparently doesn't exist for some targets.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@250068 91177308-0d34-0410-b5e6-96231b3b80d8
1 file changed