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

pkg/analyzer/lib/src/context/context.dart

Index: pkg/analyzer/lib/src/context/context.dart
diff --git a/pkg/analyzer/lib/src/context/context.dart b/pkg/analyzer/lib/src/context/context.dart
index fe33e3a99b3488fc0a1625ce349b141d8bc549e2..24bf8d5720b39952e9c5f7cb9f2d3313337ffe04 100644
--- a/pkg/analyzer/lib/src/context/context.dart
+++ b/pkg/analyzer/lib/src/context/context.dart
@@ -13,8 +13,8 @@ import 'package:analyzer/dart/element/type.dart';
 import 'package:analyzer/instrumentation/instrumentation.dart';
 import 'package:analyzer/plugin/resolver_provider.dart';
 import 'package:analyzer/plugin/task.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/dart/element/element.dart';
 import 'package:analyzer/src/dart/element/type.dart';
@@ -1251,6 +1251,7 @@ class AnalysisContextImpl implements InternalAnalysisContext {
       setValue(ResultDescriptor result, value) {
         entry.setValue(result, value, TargetedResult.EMPTY_LIST);
       }
+
       setValue(BUILD_DIRECTIVES_ERRORS, AnalysisError.NO_ERRORS);
       setValue(BUILD_LIBRARY_ERRORS, AnalysisError.NO_ERRORS);
       // CLASS_ELEMENTS
@@ -1767,6 +1768,7 @@ class AnalysisContextImpl implements InternalAnalysisContext {
       }
       return false;
     }
+
     return _refHtml(librarySource);
   }