[LV] Support sinking recipe in replicate region after another region.

This patch handles sinking a replicate region after another replicate
region. In that case, we can connect the sink region after the target
region. This properly handles the case for which an assertion has been
added in 337d7652.

Fixes https://bugs.chromium.org/p/oss-fuzz/issues/detail?id=34842.

Reviewed By: Ayal

Differential Revision: https://reviews.llvm.org/D103514