InvalidClass is also reported if the casing in the namespace is wrong (#4090)

docs/running_psalm/issues/InvalidClass.md

@@ -8,3 +8,19 @@ Emitted when referencing a class with the wrong casing
 class Foo {}
 (new foo());
 ```
+
+Could also be an issue in the namespace even if the class has the correct casing
+```php
+<?php
+
+namespace OneTwo {
+    class Three {}
+}
+
+namespace {
+    use Onetwo\Three;
+    //     ^ ("t" instead of "T")
+
+    $three = new Three();
+}
+```