Add test for class+namespace merging

Author: rbuckton

tests/cases/conformance/esDecorators/classDeclaration/esDecorators-classDeclaration-commonjs-classNamespaceMerge.ts

@@ -0,0 +1,15 @@
+// @target: es2022
+// @module: commonjs
+
+declare var deco: any;
+
+@deco
+export class Example {
+    static foo() {}
+}
+
+export namespace Example {
+    export const x = 1;
+}
+
+Example.foo();