Revert "Use pathinfo() in AutoLoaderStructureTest::testPSR4Completeness"

This reverts commit 634c2ec2af.

Reason for revert: that strips the PSR4 directories from the class.

Example:
$dir BlueSpiceFoundation/src/"
$file BlueSpiceFoundation/src/ConfigDefinition/IntSetting.php

$abbrFileName: IntSetting
$expectedClassName: BlueSpice\IntSetting

$abbrFileName should be relative to $dir and not just the filename.

Bug: T198077
Change-Id: Ie934e309fee0392439b4e26d86249f0650e5ea67

tests/phpunit/structure/AutoLoaderStructureTest.php

@@ -46,7 +46,7 @@ class AutoLoaderStructureTest extends MediaWikiTestCase {
 			// Check that the expected class name (based on the filename) is the
 			// same as the one we found.
 			// Strip directory prefix from front of filename, and .php extension
-			$abbrFileName = pathinfo( $file, PATHINFO_FILENAME );
+			$abbrFileName = substr( substr( $file, strlen( $dir ) ), 0, -4 );
 			$expectedClassName = $prefix . str_replace( '/', '\\', $abbrFileName );
 
 			$this->assertSame(