fix merge issue

lib/ModuleParseError.js

@@ -18,7 +18,10 @@ class ModuleParseError extends WebpackError {
 		let message = "Module parse failed: " + (err && err.message);
 		let loc = undefined;
 
-		if (loaders.length >= 1) {
+		if (!loaders) {
+			message +=
+				"\nYou may need an appropriate loader to handle this file type.";
+		} else if (loaders.length >= 1) {
 			message += `\nFile was processed with these loaders:${loaders
 				.map(loader => `\n * ${loader}`)
 				.join("")}`;