Add UnlinkedConst.isValid and set it during summarizing.

pkg/analyzer/test/src/summary/summary_common.dart

 // Copyright (c) 2015, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library analyzer.test.src.summary.summary_common;
 
 import 'package:analyzer/analyzer.dart';
 import 'package:analyzer/dart/ast/ast.dart';
 import 'package:analyzer/dart/element/element.dart';
 import 'package:analyzer/src/generated/engine.dart';
@@ skipping 3870 matching lines @@
   }
 
   test_field_final() {
     UnlinkedVariable variable =
         serializeClassText('class C { final int i = 0; }').fields[0];
     expect(variable.isFinal, isTrue);
     _assertUnlinkedConst(variable.constExpr,
         operators: [UnlinkedConstOperation.pushInt], ints: [0]);
   }
 
+  test_field_final_invalidConstExpr() {
+    UnlinkedVariable variable = serializeClassText(r'''
+class C {
+  final int f = 1 + m();
+  static int m() => 42;
+}''').fields[0];
+    expect(variable.isFinal, isTrue);
+    _assertUnlinkedConst(variable.constExpr, isValid: false);
+  }
+
   test_field_formal_param_inferred_type_explicit() {
     UnlinkedClass cls = serializeClassText(
         'class C extends D { var v; C(int this.v); }'
         ' abstract class D { num get v; }',
         className: 'C');
     checkInferredTypeSlot(
         cls.fields[0].inferredTypeSlot, 'dart:core', 'dart:core', 'num');
     expect(cls.executables[0].kind, UnlinkedExecutableKind.constructor);
     expect(cls.executables[0].parameters[0].inferredTypeSlot, 0);
   }
@@ skipping 1517 matching lines @@
             // This reference should have a dependency of 0, since it refers to
             // an element that is contained within some other element.
             expect(reference.dependency, 0,
                 reason: 'Nonzero dependency for ${reference.kind}');
         }
       }
     }
   }
 
   void _assertUnlinkedConst(UnlinkedConst constExpr,
-      {List<UnlinkedConstOperation> operators,
+      {bool isValid: true,
+      List<UnlinkedConstOperation> operators: const <UnlinkedConstOperation>[],
       List<int> ints: const <int>[],
       List<double> doubles: const <double>[],
       List<String> strings: const <String>[],
       List<_EntityRefValidator> referenceValidators:
           const <_EntityRefValidator>[]}) {
     expect(constExpr, isNotNull);
+    expect(constExpr.isValid, isValid);
     expect(constExpr.operations, operators);
     expect(constExpr.ints, ints);
     expect(constExpr.doubles, doubles);
     expect(constExpr.strings, strings);
     expect(constExpr.references, hasLength(referenceValidators.length));
     for (int i = 0; i < referenceValidators.length; i++) {
       referenceValidators[i](constExpr.references[i]);
     }
   }
 }
 
 /**
  * Description of expectations for a prelinked prefix reference.
  */
 class _PrefixExpectation {
   final ReferenceKind kind;
   final String name;
   final bool inLibraryDefiningUnit;
   final String absoluteUri;
   final String relativeUri;
   final int numTypeParameters;
 
   _PrefixExpectation(this.kind, this.name,
       {this.inLibraryDefiningUnit: false,
       this.absoluteUri,
       this.relativeUri,
       this.numTypeParameters: 0});
 }