Compute mixin application constructors in the ClassElement.constructors getter.

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

Index: pkg/analyzer/lib/src/generated/error_verifier.dart
diff --git a/pkg/analyzer/lib/src/generated/error_verifier.dart b/pkg/analyzer/lib/src/generated/error_verifier.dart
index 85ea9015c109dbc89c8a4ff03c5e5e76f7a0f9a6..e80e02abdd0c8528ad1717884a64134c084879e3 100644
--- a/pkg/analyzer/lib/src/generated/error_verifier.dart
+++ b/pkg/analyzer/lib/src/generated/error_verifier.dart
@@ -422,6 +422,7 @@ class ErrorVerifier extends RecursiveAstVisitor<Object> {
           _checkForConflictingInstanceGetterAndSuperclassMember();
           _checkImplementsSuperClass(node);
           _checkImplementsFunctionWithoutCall(node);
+          _checkForMixinHasNoConstructors(node);
         }
       }
       visitClassDeclarationIncrementally(node);
@@ -474,6 +475,7 @@ class ErrorVerifier extends RecursiveAstVisitor<Object> {
         _checkForImplementsDeferredClass(implementsClause);
         _checkForRecursiveInterfaceInheritance(_enclosingClass);
         _checkForNonAbstractClassInheritsAbstractMember(node.name);
+        _checkForMixinHasNoConstructors(node);
       }
     } finally {
       _enclosingClass = outerClassElement;
@@ -4165,6 +4167,18 @@ class ErrorVerifier extends RecursiveAstVisitor<Object> {
   }
 
   /**
+   * Report the error [CompileTimeErrorCode.MIXIN_HAS_NO_CONSTRUCTORS] if
+   * appropriate.
+   */
+  void _checkForMixinHasNoConstructors(AstNode node) {
+    if ((_enclosingClass as ClassElementImpl).doesMixinLackConstructors) {
+      ErrorCode errorCode = CompileTimeErrorCode.MIXIN_HAS_NO_CONSTRUCTORS;
+      _errorReporter.reportErrorForNode(
+          errorCode, node, [_enclosingClass.supertype]);
+    }
+  }
+
+  /**
    * Verify that the given mixin has the 'Object' superclass. The [mixinName] is
    * the node to report problem on. The [mixinElement] is the mixing to
    * evaluate.
@@ -4290,7 +4304,7 @@ class ErrorVerifier extends RecursiveAstVisitor<Object> {
       ClassDeclaration declaration) {
     // do nothing if mixin errors have already been reported for this class.
     ClassElementImpl enclosingClass = _enclosingClass;
-    if (enclosingClass.mixinErrorsReported) {
+    if (enclosingClass.doesMixinLackConstructors) {
       return false;
     }
     // do nothing if there is explicit constructor
@@ -5183,7 +5197,7 @@ class ErrorVerifier extends RecursiveAstVisitor<Object> {
     }
     // do nothing if mixin errors have already been reported for this class.
     ClassElementImpl enclosingClass = _enclosingClass;
-    if (enclosingClass.mixinErrorsReported) {
+    if (enclosingClass.doesMixinLackConstructors) {
       return false;
     }
     //