Only bundle the release build, and don't import src in tests (#13978)

* Only bundle the release build, and don't import `src` in tests

* Use file extension to signal skipping

* Remove unnecessary config change

* Fix imports

packages/babel-parser/test/unit/util/identifier.skip-bundled.js

@@ -0,0 +1,42 @@
+import {
+  isKeyword,
+  keywordRelationalOperator,
+} from "../../../lib/util/identifier.js";
+
+describe("identifier", () => {
+  describe("isKeyword", () => {
+    it("break is a keyword", () => {
+      expect(isKeyword("break")).toBe(true);
+    });
+    it("const is a keyword", () => {
+      expect(isKeyword("const")).toBe(true);
+    });
+    it("super is a keyword", () => {
+      expect(isKeyword("super")).toBe(true);
+    });
+    it("let is not a keyword", () => {
+      expect(isKeyword("let")).toBe(false);
+    });
+    it("abc is not a keyword", () => {
+      expect(isKeyword("abc")).toBe(false);
+    });
+  });
+
+  describe("keywordRelationalOperator", () => {
+    it("in is true", () => {
+      expect(keywordRelationalOperator.test("in")).toBe(true);
+    });
+    it("instanceof is true", () => {
+      expect(keywordRelationalOperator.test("instanceof")).toBe(true);
+    });
+    it("stanceof is false", () => {
+      expect(keywordRelationalOperator.test("stanceof")).toBe(false);
+    });
+    it("instance is false", () => {
+      expect(keywordRelationalOperator.test("instance")).toBe(false);
+    });
+    it("abc is false", () => {
+      expect(keywordRelationalOperator.test("abc")).toBe(false);
+    });
+  });
+});