Don't record absolute paths for regexps used in dynamic requires

This avoids records like:

"src/dependencies sync ../../../../^/.//.*$": "./src/dependencies sync recursive ^\\.\\/.*$"

with the number of "../"s varying according to the depth of the folder you're building from.

Fixes #7339

lib/util/identifier.js

@@ -12,6 +12,11 @@ const path = require("path");
  * @returns {boolean} returns true if path is "Absolute Path"-like
  */
 const looksLikeAbsolutePath = maybeAbsolutePath => {
+	if (/^\/.*\/$/.test(maybeAbsolutePath)) {
+		// this 'path' is actually a regexp generated by dynamic requires.
+		// Don't treat it as an absolute path.
+		return false;
+	}
 	return /^(?:[a-z]:\\|\/)/i.test(maybeAbsolutePath);
 };
 

test/__snapshots__/ConfigTestCases.test.js.snap

@@ -27,3 +27,35 @@ exports[`ConfigTestCases records issue-2991 exported tests should write relative
   }
 }"
 `;
+
+exports[`ConfigTestCases records issue-7339 exported tests should write relative dynamic-require paths to records 1`] = `
+"{
+  \\"modules\\": {
+    \\"byIdentifier\\": {
+      \\"dependencies/foo.js\\": 0,
+      \\"dependencies/bar.js\\": 1,
+      \\"external \\\\\\"path\\\\\\"\\": 2,
+      \\"external \\\\\\"fs\\\\\\"\\": 3,
+      \\"dependencies sync /^\\\\\\\\.\\\\\\\\/.*$/\\": 4,
+      \\"test.js\\": 5
+    },
+    \\"usedIds\\": {
+      \\"0\\": 0,
+      \\"1\\": 1,
+      \\"2\\": 2,
+      \\"3\\": 3,
+      \\"4\\": 4,
+      \\"5\\": 5
+    }
+  },
+  \\"chunks\\": {
+    \\"byName\\": {
+      \\"main\\": 0
+    },
+    \\"bySource\\": {},
+    \\"usedIds\\": [
+      0
+    ]
+  }
+}"
+`;

test/configCases/records/issue-7339/dependencies/bar.js

@@ -0,0 +1 @@
+module.exports = "Bar"

test/configCases/records/issue-7339/dependencies/foo.js

@@ -0,0 +1 @@
+module.exports = "Foo"

test/configCases/records/issue-7339/test.js

@@ -0,0 +1,10 @@
+function loadDependency(dep) {
+	require("./dependencies/" + dep);
+}
+
+it("should write relative dynamic-require paths to records", function() {
+	var fs = require("fs");
+	var path = require("path");
+	var content = fs.readFileSync(path.join(__dirname, "records.json"), "utf-8");
+	expect(content).toMatchSnapshot();
+});

test/configCases/records/issue-7339/webpack.config.js

@@ -0,0 +1,13 @@
+var path = require("path");
+
+module.exports = {
+	entry: "./test",
+	recordsOutputPath: path.resolve(
+		__dirname,
+		"../../../js/config/records/issue-7339/records.json"
+	),
+	target: "node",
+	node: {
+		__dirname: false
+	}
+};