Fix CLI SDK option config timing (#26129).

pkg/analyzer_cli/lib/src/analyzer_impl.dart

Index: pkg/analyzer_cli/lib/src/analyzer_impl.dart
diff --git a/pkg/analyzer_cli/lib/src/analyzer_impl.dart b/pkg/analyzer_cli/lib/src/analyzer_impl.dart
index b3e9398204828aed0b8450529f2c6499f8691f43..6c4fbcdefb1e701be0238aee6683f81f4a438cd4 100644
--- a/pkg/analyzer_cli/lib/src/analyzer_impl.dart
+++ b/pkg/analyzer_cli/lib/src/analyzer_impl.dart
@@ -13,7 +13,6 @@ import 'package:analyzer/src/generated/engine.dart';
 import 'package:analyzer/src/generated/error.dart';
 import 'package:analyzer/src/generated/java_engine.dart';
 import 'package:analyzer/src/generated/java_io.dart';
-import 'package:analyzer/src/generated/sdk_io.dart';
 import 'package:analyzer/src/generated/source.dart';
 import 'package:analyzer/src/generated/source_io.dart';
 import 'package:analyzer/src/generated/utilities_general.dart';
@@ -25,8 +24,6 @@ import 'package:path/path.dart' as pathos;
 /// The maximum number of sources for which AST structures should be kept in the cache.
 const int _maxCacheSize = 512;
 
-DirectoryBasedDartSdk sdk;
-
 int currentTimeMillis() => new DateTime.now().millisecondsSinceEpoch;
 
 /// Analyzes single library [File].