Revert "Use native async/await support in pub."

sdk/lib/_internal/pub_generated/lib/src/ascii_tree.dart

Index: sdk/lib/_internal/pub_generated/lib/src/ascii_tree.dart
diff --git a/sdk/lib/_internal/pub/lib/src/ascii_tree.dart b/sdk/lib/_internal/pub_generated/lib/src/ascii_tree.dart
similarity index 95%
copy from sdk/lib/_internal/pub/lib/src/ascii_tree.dart
copy to sdk/lib/_internal/pub_generated/lib/src/ascii_tree.dart
index d197df1b574866e43b8c88344fc28750aec4213b..ca8d5103c2b0b1c1a04775c610eb69330bd3d978 100644
--- a/sdk/lib/_internal/pub/lib/src/ascii_tree.dart
+++ b/sdk/lib/_internal/pub_generated/lib/src/ascii_tree.dart
@@ -107,7 +107,7 @@ String fromMap(Map map, {bool showAllChildren}) {
 }
 
 void _drawLine(StringBuffer buffer, String prefix, bool isLastChild,
-               String name) {
+    String name) {
   // Print lines.
   buffer.write(prefix);
   if (name != null) {
@@ -129,7 +129,7 @@ String _getPrefix(bool isRoot, bool isLast) {
 }
 
 void _draw(StringBuffer buffer, String prefix, String name, Map children,
-           {bool showAllChildren, bool isLast: false}) {
+    {bool showAllChildren, bool isLast: false}) {
   if (showAllChildren == null) showAllChildren = false;
 
   // Don't draw a line for the root node.
@@ -140,8 +140,13 @@ void _draw(StringBuffer buffer, String prefix, String name, Map children,
 
   drawChild(bool isLastChild, String child) {
     var childPrefix = _getPrefix(name == null, isLast);
-    _draw(buffer, '$prefix$childPrefix', child, children[child],
-        showAllChildren: showAllChildren, isLast: isLastChild);
+    _draw(
+        buffer,
+        '$prefix$childPrefix',
+        child,
+        children[child],
+        showAllChildren: showAllChildren,
+        isLast: isLastChild);
   }
 
   if (name == null || showAllChildren || childNames.length <= 10) {