[RISCV] Preserve tail agnostic policy in foldVMV_V_V (#105788)

This patch helps avoid regressions in an upcoming patch by making sure
we don't accidentally lose a tail agnostic policy when folding a vmv.v.v
into its source.

The previous comment about RISCVInsertVSETVLI relaxing the policy didn't
take into account the fact that there's a policy operand on vmv.v.v,
which can be tail agnostic.

If the tail is agnostic (via either the policy operand or the passthru
being undef) and vmv.v.v's VL <= Src's VL, then Src's tail can be made
agnostic.

0 files changed, 0 insertions, 0 deletions