UseListShuffleVector: Code reorganization, NFC
UseListShuffleVector: Remove copy constructor

Remove the copy constructor added in r214178 to appease MSVC17 since it
shouldn't be called at all.  My guess is that explicitly deleting it
will make the compiler happy.  To round out the operations I've also
deleted copy assignment and added move assignment.  Otherwise no
functionality change.
gold plugin: Fix handling of corrupted bitcode files.

We should still claim them and tell gold about the error.