Remove the capture mode map and just store the capture mode for individual variables.

Also add test. Fixes #16749.

src/librustc_resolve/lib.rs

@@ -62,7 +62,7 @@ use rustc::middle::lang_items::LanguageItems;
 use rustc::middle::pat_util::pat_bindings;
 use rustc::middle::privacy::*;
 use rustc::middle::subst::{ParamSpace, FnSpace, TypeSpace};
-use rustc::middle::ty::{CaptureModeMap, Freevar, FreevarMap, TraitMap, GlobMap};
+use rustc::middle::ty::{Freevar, FreevarMap, TraitMap, GlobMap};
 use rustc::util::nodemap::{NodeMap, NodeSet, DefIdSet, FnvHashMap};
 use rustc::util::lev_distance::lev_distance;
 
@@ -900,7 +900,6 @@ struct Resolver<'a, 'tcx:'a> {
     def_map: DefMap,
     freevars: RefCell<FreevarMap>,
     freevars_seen: RefCell<NodeMap<NodeSet>>,
-    capture_mode_map: CaptureModeMap,
     export_map: ExportMap,
     trait_map: TraitMap,
     external_exports: ExternalExports,
@@ -974,7 +973,6 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
             def_map: RefCell::new(NodeMap()),
             freevars: RefCell::new(NodeMap()),
             freevars_seen: RefCell::new(NodeMap()),
-            capture_mode_map: NodeMap(),
             export_map: NodeMap(),
             trait_map: NodeMap(),
             used_imports: HashSet::new(),
@@ -4523,8 +4521,7 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
                 visit::walk_expr(self, expr);
             }
 
-            ExprClosure(capture_clause, _, ref fn_decl, ref block) => {
-                self.capture_mode_map.insert(expr.id, capture_clause);
+            ExprClosure(_, _, ref fn_decl, ref block) => {
                 self.resolve_function(ClosureRibKind(expr.id),
                                       Some(&**fn_decl), NoTypeParameters,
                                       &**block);
@@ -4835,7 +4832,6 @@ impl<'a, 'tcx> Resolver<'a, 'tcx> {
 pub struct CrateMap {
     pub def_map: DefMap,
     pub freevars: RefCell<FreevarMap>,
-    pub capture_mode_map: RefCell<CaptureModeMap>,
     pub export_map: ExportMap,
     pub trait_map: TraitMap,
     pub external_exports: ExternalExports,
@@ -4875,7 +4871,6 @@ pub fn resolve_crate<'a, 'tcx>(session: &'a Session,
     CrateMap {
         def_map: resolver.def_map,
         freevars: resolver.freevars,
-        capture_mode_map: RefCell::new(resolver.capture_mode_map),
         export_map: resolver.export_map,
         trait_map: resolver.trait_map,
         external_exports: resolver.external_exports,