Revert "New implementation of {,Linked}Hash{Set,Map}."

sdk/lib/_internal/compiler/implementation/source_map_builder.dart

Index: sdk/lib/_internal/compiler/implementation/source_map_builder.dart
diff --git a/sdk/lib/_internal/compiler/implementation/source_map_builder.dart b/sdk/lib/_internal/compiler/implementation/source_map_builder.dart
index 80960d3f407299a064a6a6a99ea6a803ea9509a6..a2cd6fcc337e36d4acc7d20b022b881387aaafb5 100644
--- a/sdk/lib/_internal/compiler/implementation/source_map_builder.dart
+++ b/sdk/lib/_internal/compiler/implementation/source_map_builder.dart
@@ -134,6 +134,7 @@ class SourceMapBuilder {
   int indexOf(List<String> list, String value, Map<String, int> map) {
     return map.putIfAbsent(value, () {
       int index = list.length;
+      map[value] = index;
       list.add(value);
       return index;
     });