Move embedder locator and convert context builder to use the new API

pkg/analyzer/lib/src/generated/engine.dart

Index: pkg/analyzer/lib/src/generated/engine.dart
diff --git a/pkg/analyzer/lib/src/generated/engine.dart b/pkg/analyzer/lib/src/generated/engine.dart
index 967095a22447dd9ce6f8d4abf180cb2375fc59c3..b229169be6edf5ac1ee6f35f48287b3cbaf8a195 100644
--- a/pkg/analyzer/lib/src/generated/engine.dart
+++ b/pkg/analyzer/lib/src/generated/engine.dart
@@ -12,8 +12,8 @@ import 'package:analyzer/dart/ast/visitor.dart';
 import 'package:analyzer/dart/element/element.dart';
 import 'package:analyzer/instrumentation/instrumentation.dart';
 import 'package:analyzer/plugin/resolver_provider.dart';
-import 'package:analyzer/source/embedder.dart';
 import 'package:analyzer/src/cancelable_future.dart';
+import 'package:analyzer/src/context/builder.dart' show EmbedderYamlLocator;
 import 'package:analyzer/src/context/cache.dart';
 import 'package:analyzer/src/context/context.dart';
 import 'package:analyzer/src/generated/constant.dart';
@@ -1456,6 +1456,7 @@ class AnalysisOptionsImpl implements AnalysisOptions {
       buffer.write(optionName);
       needsSeparator = true;
     }
+
     if (encoding & ENABLE_ASSERT_FLAG > 0) {
       add('assert');
     }