Fix PHPT coverage from phpdbg

Fixes #3111.
Stop using auto_append_file as it doesn't work with the phpdbg sapi.
Instead, the job's code is written to a temp file and the coverage instrumentation code takes over the code.

src/Runner/PhptTestCase.php

@@ -150,7 +150,7 @@ public function run(TestResult $result = null): TestResult
         }
 
         if ($result->getCollectCodeCoverageInformation()) {
-            $this->renderForCoverage($settings);
+            $this->renderForCoverage($code);
         }
 
         Timer::start();
@@ -488,7 +488,7 @@ private function getCoverageFiles(): array
         ];
     }
 
-    private function renderForCoverage(array &$settings): void
+    private function renderForCoverage(string &$job): void
     {
         $files = $this->getCoverageFiles();
 
@@ -520,24 +520,23 @@ private function renderForCoverage(array &$settings): void
                 'phar'             => $phar,
                 'globals'          => $globals,
                 'job'              => $files['job'],
-                'coverageFile'     => $files['coverage'],
-                'autoPrependFile'  => \var_export(
-                    !empty($settings['auto_prepend_file']) ? $settings['auto_prepend_file'] : false,
-                    true
-                )
+                'coverageFile'     => $files['coverage']
             ]
         );
 
-        \file_put_contents($files['job'], $template->render());
-
-        $settings['auto_prepend_file'] = $files['job'];
+        \file_put_contents($files['job'], $job);
+        $job = $template->render();
     }
 
     private function cleanupForCoverage(): array
     {
         $files    = $this->getCoverageFiles();
         $coverage = @\unserialize(\file_get_contents($files['coverage']));
 
+        if ($coverage === false) {
+            $coverage = [];
+        }
+
         foreach ($files as $file) {
             @\unlink($file);
         }

src/Util/PHP/Template/PhptTestCase.tpl.dist

@@ -3,7 +3,6 @@ use SebastianBergmann\CodeCoverage\CodeCoverage;
 
 $composerAutoload = {composerAutoload};
 $phar             = {phar};
-$autoPrependFile  = {autoPrependFile};
 
 ob_start();
 
@@ -28,7 +27,7 @@ if (class_exists('SebastianBergmann\CodeCoverage\CodeCoverage')) {
     $coverage->start(__FILE__);
 }
 
-register_shutdown_function(function() use ($coverage, $autoPrependFile) {
+register_shutdown_function(function() use ($coverage) {
     $output = null;
     if ($coverage) {
         $output = $coverage->stop();
@@ -38,9 +37,4 @@ register_shutdown_function(function() use ($coverage, $autoPrependFile) {
 
 ob_end_clean();
 
-if ($autoPrependFile) {
-    require $autoPrependFile;
-    $includes = get_included_files();
-    $GLOBALS['__PHPUNIT_ISOLATION_BLACKLIST'][] = array_pop($includes);
-    unset($includes);
-}
+require '{job}';