Add a public API for the results of constant evaluation

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

Index: pkg/analyzer/lib/src/generated/resolver.dart
diff --git a/pkg/analyzer/lib/src/generated/resolver.dart b/pkg/analyzer/lib/src/generated/resolver.dart
index 84f0f6b2bccd175b8f2f3cef08dd0f8da37aa873..47a68ee9fd1bd1b16266b070b1e7f5d5d7126706 100644
--- a/pkg/analyzer/lib/src/generated/resolver.dart
+++ b/pkg/analyzer/lib/src/generated/resolver.dart
@@ -1521,14 +1521,14 @@ class DeadCodeVerifier extends RecursiveAstVisitor<Object> {
       if (!_isDebugConstant(lhsCondition)) {
         EvaluationResultImpl lhsResult = _getConstantBooleanValue(lhsCondition);
         if (lhsResult != null) {
-          if (lhsResult.value.isTrue && isBarBar) {
+          if (lhsResult.value.toBoolValue() == true && isBarBar) {
             // report error on else block: true || !e!
             _errorReporter.reportErrorForNode(
                 HintCode.DEAD_CODE, node.rightOperand);
             // only visit the LHS:
             _safelyVisit(lhsCondition);
             return null;
-          } else if (lhsResult.value.isFalse && isAmpAmp) {
+          } else if (lhsResult.value.toBoolValue() == false && isAmpAmp) {
             // report error on if block: false && !e!
             _errorReporter.reportErrorForNode(
                 HintCode.DEAD_CODE, node.rightOperand);
@@ -1582,7 +1582,7 @@ class DeadCodeVerifier extends RecursiveAstVisitor<Object> {
       EvaluationResultImpl result =
           _getConstantBooleanValue(conditionExpression);
       if (result != null) {
-        if (result.value.isTrue) {
+        if (result.value.toBoolValue() == true) {
           // report error on else block: true ? 1 : !2!
           _errorReporter.reportErrorForNode(
               HintCode.DEAD_CODE, node.elseExpression);
@@ -1608,7 +1608,7 @@ class DeadCodeVerifier extends RecursiveAstVisitor<Object> {
       EvaluationResultImpl result =
           _getConstantBooleanValue(conditionExpression);
       if (result != null) {
-        if (result.value.isTrue) {
+        if (result.value.toBoolValue() == true) {
           // report error on else block: if(true) {} else {!}
           Statement elseStatement = node.elseStatement;
           if (elseStatement != null) {
@@ -1717,7 +1717,7 @@ class DeadCodeVerifier extends RecursiveAstVisitor<Object> {
       EvaluationResultImpl result =
           _getConstantBooleanValue(conditionExpression);
       if (result != null) {
-        if (result.value.isFalse) {
+        if (result.value.toBoolValue() == false) {
           // report error on if block: while (false) {!}
           _errorReporter.reportErrorForNode(HintCode.DEAD_CODE, node.body);
           return null;
@@ -15722,11 +15722,6 @@ class VariableResolverVisitor extends ScopedVisitor {
   }
 
   @override
-  Object visitTypeName(TypeName node) {
-    return null;
-  }
-
-  @override
   Object visitSimpleIdentifier(SimpleIdentifier node) {
     // Ignore if already resolved - declaration or type.
     if (node.inDeclarationContext()) {
@@ -15738,7 +15733,8 @@ class VariableResolverVisitor extends ScopedVisitor {
       return null;
     } else if (parent is ConstructorDeclaration && parent.returnType == node) {
       return null;
-    } else if (parent is ConstructorFieldInitializer && parent.fieldName == node) {
+    } else if (parent is ConstructorFieldInitializer &&
+        parent.fieldName == node) {
       return null;
     }
     // Ignore if qualified.
@@ -15791,6 +15787,11 @@ class VariableResolverVisitor extends ScopedVisitor {
     }
     return null;
   }
+
+  @override
+  Object visitTypeName(TypeName node) {
+    return null;
+  }
 }
 
 class _ConstantVerifier_validateInitializerExpression extends ConstantVisitor {