DB/PreparedSQL: move intentional syntax error test to its own file

Author: rodrigoprimo

WordPress/Tests/DB/PreparedSQLUnitTest.1.inc

@@ -142,6 +142,3 @@ echo $wpdb::CONSTANT_NAME;
 
 // Not an identifiable method call.
 $wpdb->{$methodName}('query');
-
-// Don't throw an error during live coding.
-wpdb::prepare( "SELECT * FROM $wpdb->posts

WordPress/Tests/DB/PreparedSQLUnitTest.3.inc

@@ -0,0 +1,8 @@
+<?php
+
+/*
+ * Intentional parse error (unclosed string).
+ * This should be the only test in this file.
+ */
+
+wpdb::prepare( "SELECT * FROM $wpdb->posts