Add ClassAugmentationDeclarationImpl, parse into it.

Change-Id: I2461cffa76f31079e52f9877b9fe35668811191b
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/312346
Reviewed-by: Brian Wilkerson <[email protected]>
Commit-Queue: Konstantin Shcheglov <[email protected]>

Author: scheglov

pkg/analyzer/lib/dart/ast/visitor.dart

@@ -196,6 +196,10 @@ class GeneralizingAstVisitor<R> implements AstVisitor<R> {
   @override
   R? visitCatchClauseParameter(CatchClauseParameter node) => visitNode(node);
 
+  @override
+  R? visitClassAugmentationDeclaration(ClassAugmentationDeclaration node) =>
+      visitNamedCompilationUnitMember(node);
+
   @override
   R? visitClassDeclaration(ClassDeclaration node) =>
       visitNamedCompilationUnitMember(node);
@@ -901,6 +905,12 @@ class RecursiveAstVisitor<R> implements AstVisitor<R> {
     return null;
   }
 
+  @override
+  R? visitClassAugmentationDeclaration(ClassAugmentationDeclaration node) {
+    node.visitChildren(this);
+    return null;
+  }
+
   @override
   R? visitClassDeclaration(ClassDeclaration node) {
     node.visitChildren(this);
@@ -1858,6 +1868,10 @@ class SimpleAstVisitor<R> implements AstVisitor<R> {
   @override
   R? visitCatchClauseParameter(CatchClauseParameter node) => null;
 
+  @override
+  R? visitClassAugmentationDeclaration(ClassAugmentationDeclaration node) =>
+      null;
+
   @override
   R? visitClassDeclaration(ClassDeclaration node) => null;
 
@@ -2387,6 +2401,10 @@ class ThrowingAstVisitor<R> implements AstVisitor<R> {
   @override
   R? visitCatchClauseParameter(CatchClauseParameter node) => _throw(node);
 
+  @override
+  R? visitClassAugmentationDeclaration(ClassAugmentationDeclaration node) =>
+      _throw(node);
+
   @override
   R? visitClassDeclaration(ClassDeclaration node) => _throw(node);
 
@@ -3035,6 +3053,14 @@ class TimedAstVisitor<T> implements AstVisitor<T> {
     return result;
   }
 
+  @override
+  T? visitClassAugmentationDeclaration(ClassAugmentationDeclaration node) {
+    stopwatch.start();
+    T? result = _baseVisitor.visitClassAugmentationDeclaration(node);
+    stopwatch.stop();
+    return result;
+  }
+
   @override
   T? visitClassDeclaration(ClassDeclaration node) {
     stopwatch.start();
@@ -4293,6 +4319,10 @@ class UnifyingAstVisitor<R> implements AstVisitor<R> {
   @override
   R? visitCatchClauseParameter(CatchClauseParameter node) => visitNode(node);
 
+  @override
+  R? visitClassAugmentationDeclaration(ClassAugmentationDeclaration node) =>
+      visitNode(node);
+
   @override
   R? visitClassDeclaration(ClassDeclaration node) => visitNode(node);