Take MIR dataflow analyses by mutable reference.

compiler/rustc_borrowck/src/lib.rs

@@ -372,7 +372,7 @@ fn do_mir_borrowck<'tcx>(
     // Compute and report region errors, if any.
     mbcx.report_region_errors(nll_errors);
 
-    let results = BorrowckResults {
+    let mut results = BorrowckResults {
         ever_inits: flow_ever_inits,
         uninits: flow_uninits,
         borrows: flow_borrows,
@@ -383,7 +383,7 @@ fn do_mir_borrowck<'tcx>(
     rustc_mir_dataflow::visit_results(
         body,
         traversal::reverse_postorder(body).map(|(bb, _)| bb),
-        &results,
+        &mut results,
         &mut mbcx,
     );
 
@@ -618,11 +618,12 @@ struct MirBorrowckCtxt<'cx, 'tcx> {
 // 2. loans made in overlapping scopes do not conflict
 // 3. assignments do not affect things loaned out as immutable
 // 4. moves do not affect things loaned out in any way
-impl<'cx, 'tcx> rustc_mir_dataflow::ResultsVisitor<'cx, 'tcx> for MirBorrowckCtxt<'cx, 'tcx> {
+impl<'cx, 'tcx, R> rustc_mir_dataflow::ResultsVisitor<'cx, 'tcx, R> for MirBorrowckCtxt<'cx, 'tcx> {
     type FlowState = Flows<'cx, 'tcx>;
 
     fn visit_statement_before_primary_effect(
         &mut self,
+        _results: &R,
         flow_state: &Flows<'cx, 'tcx>,
         stmt: &'cx Statement<'tcx>,
         location: Location,
@@ -692,6 +693,7 @@ impl<'cx, 'tcx> rustc_mir_dataflow::ResultsVisitor<'cx, 'tcx> for MirBorrowckCtx
 
     fn visit_terminator_before_primary_effect(
         &mut self,
+        _results: &R,
         flow_state: &Flows<'cx, 'tcx>,
         term: &'cx Terminator<'tcx>,
         loc: Location,
@@ -800,6 +802,7 @@ impl<'cx, 'tcx> rustc_mir_dataflow::ResultsVisitor<'cx, 'tcx> for MirBorrowckCtx
 
     fn visit_terminator_after_primary_effect(
         &mut self,
+        _results: &R,
         flow_state: &Flows<'cx, 'tcx>,
         term: &'cx Terminator<'tcx>,
         loc: Location,