[test] Support dumping rendered diagnostics from multiple modules

js/js.tests/test/org/jetbrains/kotlin/js/test/handlers/JsBackendDiagnosticsHandler.kt

@@ -15,8 +15,9 @@ import org.jetbrains.kotlin.test.services.*
 class JsBackendDiagnosticsHandler(testServices: TestServices) : KlibArtifactHandler(testServices) {
     override fun processModule(module: TestModule, info: BinaryArtifacts.KLib) {
         reportKtDiagnostics(module, info.reporter)
-        checkFullDiagnosticRender(module)
     }
 
-    override fun processAfterAllModules(someAssertionWasFailed: Boolean) {}
+    override fun processAfterAllModules(someAssertionWasFailed: Boolean) {
+        checkFullDiagnosticRender()
+    }
 }