Address reviewers comments

Author: odersky

compiler/src/dotty/tools/dotc/ast/Trees.scala

@@ -1306,8 +1306,8 @@ object Trees {
           case Thicket(ts) =>
             this(x, ts)
           case _ if ctx.mode.is(Mode.Interactive) =>
-            // in case of errors it may be that typed trees point to untyped ones.
-            // The can still traverse inside such trees, either in the run where errors
+            // In case of errors it may be that typed trees point to untyped ones.
+            // The IDE can still traverse inside such trees, either in the run where errors
             // are reported, or in subsequent ones.
             x
         }

compiler/src/dotty/tools/dotc/core/Types.scala

@@ -1538,7 +1538,8 @@ object Types {
               else recomputeMember(d) // symbol could have been overridden, recompute membership
             else {
               val newd = loadDenot
-              if (newd.exists || ctx.mode.is(Mode.Interactive)) newd
+              if (newd.exists) newd
+              else if (ctx.mode.is(Mode.Interactive)) d
               else d.staleSymbolError
             }
           case d =>