optimization.sideEffects is compatible with cacheUnaffected

lib/optimize/SideEffectsFlagPlugin.js

@@ -235,12 +235,6 @@ class SideEffectsFlagPlugin {
 						stage: STAGE_DEFAULT
 					},
 					modules => {
-						if (compilation.moduleMemCaches) {
-							throw new Error(
-								"optimization.sideEffects can't be used with cacheUnaffected as side effects optimization is a global effect"
-							);
-						}
-
 						const logger = compilation.getLogger(
 							"webpack.SideEffectsFlagPlugin"
 						);

test/WatchCacheUnaffectedTestCases.longtest.js

@@ -4,8 +4,5 @@ describeCases({
 	name: "WatchCacheUnaffectedTestCases",
 	experiments: {
 		cacheUnaffected: true
-	},
-	optimization: {
-		sideEffects: false
 	}
 });