Preserve metadata on masked intrinsics in auto-upgrade

When auto-upgrade was replacing a call to a masked intrinsic, it would
not copy the metadata from the original call.

If an intrinsic had metadata, but did not need any updates, the metadata
would stay, but if an update was needed, the would end up being removed.
A similar effect could be observed with masked_expandload and
masked_compressstore, which at the moment are not handled by auto-upgrade:
the metadata remained untouched.

Differential Revision: https://reviews.llvm.org/D101201