fix: handle star import name collisions in module concatenation

lib/optimize/ConcatenatedModule.js

@@ -1125,7 +1125,7 @@ class ConcatenatedModule extends Module {
 						info.module.readableIdentifier(requestShortener)
 					);
 					allUsedNames.add(externalName);
-					info.name = externalName;
+					info.name = externalName + "__WEBPACK_CONCAT_EXTERNAL_";
 					break;
 				}
 			}

test/cases/optimize/concat-star-import/index.js

@@ -0,0 +1,5 @@
+import { foo } from "./module";
+
+it("should handle star import with name collision", () => {
+	expect(foo()).toBe("1 21 2");
+});

test/cases/optimize/concat-star-import/module.js

@@ -0,0 +1,7 @@
+import * as c from "cmodule";
+
+export function foo() {
+	// variable name matches the imported package name
+	const cmodule = c([1, 2]);
+	return cmodule + cmodule;
+}