Handle `new Object()` in compile_from_dill_test

pkg/compiler/lib/src/kernel/element_map_impl.dart

Index: pkg/compiler/lib/src/kernel/element_map_impl.dart
diff --git a/pkg/compiler/lib/src/kernel/element_map_impl.dart b/pkg/compiler/lib/src/kernel/element_map_impl.dart
index 0b3e7486e72832fa93e54a966d478dffdd999362..2155286e407641add795795875ac6979f264a28f 100644
--- a/pkg/compiler/lib/src/kernel/element_map_impl.dart
+++ b/pkg/compiler/lib/src/kernel/element_map_impl.dart
@@ -155,6 +155,11 @@ class KernelToElementMapImpl extends KernelToElementMapMixin {
     });
   }
 
+  String _getLibraryName(KLibrary library) {
+    _KLibraryEnv libraryEnv = _libraryEnvs[library.libraryIndex];
+    return libraryEnv.library.name ?? '';
+  }
+
   MemberEntity lookupLibraryMember(KLibrary library, String name,
       {bool setter: false}) {
     _KLibraryEnv libraryEnv = _libraryEnvs[library.libraryIndex];
@@ -1107,6 +1112,11 @@ class KernelElementEnvironment implements ElementEnvironment {
   Iterable<LibraryEntity> get libraries => elementMap._libraries;
 
   @override
+  String getLibraryName(LibraryEntity library) {
+    return elementMap._getLibraryName(library);
+  }
+
+  @override
   InterfaceType getThisType(ClassEntity cls) {
     return elementMap.getThisType(cls);
   }