Remove DropAndReplace terminator

PR 107844 made DropAndReplace unused, let's remove it completely
from the codebase.

compiler/rustc_mir_transform/src/coverage/spans.rs

@@ -850,7 +850,6 @@ pub(super) fn filtered_terminator_span(terminator: &Terminator<'_>) -> Option<Sp
         TerminatorKind::Unreachable // Unreachable blocks are not connected to the MIR CFG
         | TerminatorKind::Assert { .. }
         | TerminatorKind::Drop { .. }
-        | TerminatorKind::DropAndReplace { .. }
         | TerminatorKind::SwitchInt { .. }
         // For `FalseEdge`, only the `real` branch is taken, so it is similar to a `Goto`.
         | TerminatorKind::FalseEdge { .. }