Auto merge of #147804 - tmiasko:move-copy, r=cjgillot,saethlin

Turn moves into copies after copy propagation

Previously copy propagation presumed that there is further unspecified distinction between move operands and copy operands in assignments and propagated moves from assignments into terminators. This is inconsistent with current operational semantics.

Turn moves into copies after copy propagation to preserve existing behavior.

Fixes rust-lang/rust#137936.
Fixes rust-lang/rust#146423.

r? `@cjgillot`

Author: bors