Move WriteInfo out of Allocations.

It doesn't need to be in there, and the move simplifies lifetimes.

Author: nnethercote

compiler/rustc_mir_transform/src/dest_prop.rs

@@ -165,6 +165,7 @@ impl<'tcx> MirPass<'tcx> for DestinationPropagation {
 fnrun_pass(&self,tcx:TyCtxt<'tcx>,body:&mutBody<'tcx>){
 let def_id = body.source.def_id();
 letmut allocations = Allocations::default();
+letmut write_info = WriteInfo::default();
 trace!(func = ?tcx.def_path_str(def_id));
 
 let borrowed = rustc_mir_dataflow::impls::borrowed_locals(body);
@@ -205,7 +206,7 @@ impl<'tcx> MirPass<'tcx> for DestinationPropagation {
 &mut candidates,
 &points,
 &live,
-&mutallocations.write_info,
+&mut write_info,
  body,
 );
 
@@ -262,7 +263,6 @@ impl<'tcx> MirPass<'tcx> for DestinationPropagation {
 structAllocations{
 candidates:FxIndexMap<Local,Vec<Local>>,
 candidates_reverse:FxIndexMap<Local,Vec<Local>>,
-write_info:WriteInfo,
 // PERF: Do this for `MaybeLiveLocals` allocations too.
 }
 
@@ -364,7 +364,7 @@ struct FilterInformation<'a, 'alloc, 'tcx> {
 points:&'aDenseLocationMap,
 live:&'aSparseIntervalMatrix<Local,PointIndex>,
 candidates:&'amutCandidates<'alloc>,
-write_info:&'allocmutWriteInfo,
+write_info:&'amutWriteInfo,
 at:Location,
 }
 
@@ -468,7 +468,7 @@ impl<'a, 'alloc, 'tcx> FilterInformation<'a, 'alloc, 'tcx> {
 candidates:&mutCandidates<'alloc>,
 points:&DenseLocationMap,
 live:&SparseIntervalMatrix<Local,PointIndex>,
-write_info:&'allocmutWriteInfo,
+write_info:&mutWriteInfo,
 body:&Body<'tcx>,
 ){
 letmut this = FilterInformation{