fix(glue): expose CfnTable as defaultChild (#4197)

* fix(glue): export CfnTable defaultChild

* chore: better defaultChild test

packages/@aws-cdk/aws-glue/lib/table.ts

@@ -284,6 +284,7 @@ export class Table extends Resource implements ITable {
       resource: 'table',
       resourceName: `${this.database.databaseName}/${this.tableName}`
     });
+    this.node.defaultChild = tableResource;
   }
 
   /**

packages/@aws-cdk/aws-glue/test/test.table.ts

@@ -223,6 +223,30 @@ export = {
     test.done();
   },
 
+  'table.node.defaultChild'(test: Test) {
+    // GIVEN
+    const stack = new cdk.Stack();
+    const database = new glue.Database(stack, 'Database', {
+      databaseName: 'database',
+    });
+
+    // WHEN
+    const table = new glue.Table(stack, 'Table', {
+      database,
+      tableName: 'table',
+      columns: [{
+        name: 'col',
+        type: glue.Schema.STRING
+      }],
+      compressed: true,
+      dataFormat: glue.DataFormat.Json,
+    });
+
+    // THEN
+    test.ok(table.node.defaultChild instanceof glue.CfnTable);
+    test.done();
+  },
+
   'encrypted table': {
     'SSE-S3'(test: Test) {
       const stack = new cdk.Stack();