Add put/getSourceErrorsInLibrary to IncrementalCache.

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

Index: pkg/analyzer/lib/src/generated/error.dart
diff --git a/pkg/analyzer/lib/src/generated/error.dart b/pkg/analyzer/lib/src/generated/error.dart
index 9fb06c563b6c2893336d98d27a9ef6cd9e533403..dcf3bf922544fee4be8bd2d7f8c8168624413467 100644
--- a/pkg/analyzer/lib/src/generated/error.dart
+++ b/pkg/analyzer/lib/src/generated/error.dart
@@ -11,6 +11,7 @@ import 'package:analyzer/dart/ast/token.dart';
 import 'package:analyzer/dart/element/element.dart';
 import 'package:analyzer/dart/element/type.dart';
 import 'package:analyzer/source/error_processor.dart';
+import 'package:analyzer/src/dart/element/element.dart';
 import 'package:analyzer/src/dart/element/type.dart';
 import 'package:analyzer/src/dart/scanner/scanner.dart' show ScannerErrorCode;
 import 'package:analyzer/src/generated/generated/shared_messages.dart'
@@ -21,7 +22,6 @@ import 'package:analyzer/src/generated/source.dart';
 import 'package:analyzer/src/task/model.dart';
 import 'package:analyzer/task/model.dart';
 import 'package:source_span/source_span.dart';
-import 'package:analyzer/src/dart/element/element.dart';
 
 /**
  * The descriptor used to associate error processors with analysis contexts in
@@ -123,6 +123,12 @@ class AnalysisError {
   }
 
   /**
+   * Initialize a newly created analysis error with given values.
+   */
+  AnalysisError.forValues(this.source, this.offset, this.length, this.errorCode,
+      this._message, this._correction);
+
+  /**
    * Return the template used to create the correction to be displayed for this
    * error, or `null` if there is no correction information for this error. The
    * correction should indicate how the user can fix the error.