Update deprecation messages for exports/imports.

Change-Id: Ie9ab59d12946de7281d45c18731d6ed7cd192487
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/252000
Commit-Queue: Konstantin Shcheglov <[email protected]>
Reviewed-by: Brian Wilkerson <[email protected]>

Author: scheglov

pkg/analyzer/lib/dart/element/element.dart

@@ -1626,7 +1626,7 @@ abstract class LibraryOrAugmentationElement implements Element {
   CompilationUnitElement get definingCompilationUnit;
 
   /// Return a list containing all of the exports defined in this library.
-  @Deprecated('Use exports2 instead')
+  @Deprecated('Use libraryExports instead')
   List<ExportElement> get exports;
 
   /// The set of features available to this library.
@@ -1637,7 +1637,7 @@ abstract class LibraryOrAugmentationElement implements Element {
   FeatureSet get featureSet;
 
   /// Return a list containing all of the imports defined in this library.
-  @Deprecated('Use imports2 instead')
+  @Deprecated('Use libraryImports instead')
   List<ImportElement> get imports;
 
   bool get isNonNullableByDefault;

pkg/analyzer/lib/src/dart/element/element.dart

@@ -4022,14 +4022,6 @@ class LibraryElementImpl extends LibraryOrAugmentationElementImpl
     _exportNamespace = exportNamespace;
   }
 
-  @Deprecated('Use exports2 instead')
-  @override
-  List<ExportElement> get exports {
-    return libraryExports
-        .map((e) => ExportElementImpl(e as LibraryExportElementImpl))
-        .toList();
-  }
-
   bool get hasPartOfDirective {
     return hasModifier(Modifier.HAS_PART_OF_DIRECTIVE);
   }
@@ -4050,14 +4042,6 @@ class LibraryElementImpl extends LibraryOrAugmentationElementImpl
         .toList();
   }
 
-  @Deprecated('Use imports2 instead')
-  @override
-  List<ImportElement> get imports {
-    return libraryImports
-        .map((e) => ImportElementImpl(e as LibraryImportElementImpl))
-        .toList();
-  }
-
   @override
   bool get isBrowserApplication =>
       entryPoint != null && isOrImportsBrowserLibrary;
@@ -4573,7 +4557,7 @@ abstract class LibraryOrAugmentationElementImpl extends ElementImpl
     return _definingCompilationUnit;
   }
 
-  @Deprecated('Use exports2 instead')
+  @Deprecated('Use libraryExports instead')
   @override
   List<ExportElement> get exports {
     return libraryExports
@@ -4588,7 +4572,7 @@ abstract class LibraryOrAugmentationElementImpl extends ElementImpl
   @override
   String get identifier => '${_definingCompilationUnit.source.uri}';
 
-  @Deprecated('Use imports2 instead')
+  @Deprecated('Use libraryImports instead')
   @override
   List<ImportElement> get imports {
     return libraryImports