rustc_mir: fix inliner to also copy over source_scope_local_data.

src/librustc_mir/transform/inline.rs

@@ -388,16 +388,25 @@ impl Inliner<'tcx> {
                 let mut local_map = IndexVec::with_capacity(callee_body.local_decls.len());
                 let mut scope_map = IndexVec::with_capacity(callee_body.source_scopes.len());
 
-                for mut scope in callee_body.source_scopes.iter().cloned() {
+                for (callee_idx, scope) in callee_body.source_scopes.iter_enumerated() {
+                    let mut scope = scope.clone();
                     if scope.parent_scope.is_none() {
                         scope.parent_scope = Some(callsite.location.scope);
+                        // FIXME(eddyb) is this really needed?
+                        // (also note that it's always overwritten below)
                         scope.span = callee_body.span;
                     }
 
+                    // FIXME(eddyb) this doesn't seem right at all.
+                    // The inlined source scopes should probably be annotated as
+                    // such, but also contain all of the original information.
                     scope.span = callsite.location.span;
 
                     let idx = caller_body.source_scopes.push(scope);
                     scope_map.push(idx);
+
+                    let local_data = callee_body.source_scope_local_data[callee_idx].clone();
+                    assert_eq!(idx, caller_body.source_scope_local_data.push(local_data));
                 }
 
                 for loc in callee_body.vars_and_temps_iter() {