Create separate scopes for constructors, setters, and other members.

pkg/front_end/lib/src/fasta/import.dart

Index: pkg/front_end/lib/src/fasta/import.dart
diff --git a/pkg/front_end/lib/src/fasta/import.dart b/pkg/front_end/lib/src/fasta/import.dart
index c8a943bb50649b67303b880743f648d95ff095f9..9c5b205dc0fa8a65b9c9c5fcb6f3a9413a3684f4 100644
--- a/pkg/front_end/lib/src/fasta/import.dart
+++ b/pkg/front_end/lib/src/fasta/import.dart
@@ -38,10 +38,13 @@ class Import {
         importer.addToScope(name, member, charOffset, true);
       };
     } else {
-      prefix = new PrefixBuilder(
-          this.prefix, <String, Builder>{}, importer, prefixCharOffset);
+      prefix = new PrefixBuilder(this.prefix, importer, prefixCharOffset);
       add = (String name, Builder member) {
-        prefix.exports[name] = member;
+        if (member.isSetter) {
+          prefix.exports.setters[name] = member;
+        } else {
+          prefix.exports.local[name] = member;
+        }
       };
     }
     imported.exports.forEach((String name, Builder member) {