Revert "Chore: rewrite parseListConfig for a small perf gain." (#9325)

* Revert "4.7.0"

This reverts commit 439e8e6.

* Revert "Build: changelog update for 4.7.0"

This reverts commit 2ec62f9.

* Revert "Upgrade: Espree v3.5.1 (fixes #9153) (#9314)"

This reverts commit 787b78b.

* Revert "Update: run rules after `node.parent` is already set (fixes #9122) (#9283)"

This reverts commit 1488b51.

* Revert "Docs: fix wrong config in max-len example. (#9309)"

This reverts commit 4431d68.

* Revert "Chore: Revert "avoid handling Rules instances in config-validator" (#9295)"

This reverts commit 9d1df92.

* Revert "Docs: Fix code snippet to refer to the correct option (#9313)"

This reverts commit 7d24dde.

* Revert "�Chore: rewrite parseListConfig for a small perf gain. (#9300)"

This reverts commit 12388d4.

lib/linter.js

@@ -146,15 +146,17 @@ function parseJsonConfig(string, location) {
  */
 function parseListConfig(string) {
     const items = {};
-    const reg = /[\w\-/]+/g;
-    const elementMatches = string.match(reg);
 
-    if (elementMatches) {
-        elementMatches.forEach(name => {
-            items[name] = true;
-        });
-    }
+    // Collapse whitespace around ,
+    string = string.replace(/\s*,\s*/g, ",");
 
+    string.split(/,+/).forEach(name => {
+        name = name.trim();
+        if (!name) {
+            return;
+        }
+        items[name] = true;
+    });
     return items;
 }