Ignore generated files by tests in extension skeleton

Closes GH-7523.

Author: rjorel

ext/skeleton/.gitignore.in

@@ -26,10 +26,16 @@ Makefile.objects
 missing
 mkinstalldirs
 modules
+php_test_results_*.txt
+phpt.*
+run-test-info.php
 run-tests.php
-tests/*/*.diff
-tests/*/*.out
-tests/*/*.php
-tests/*/*.exp
-tests/*/*.log
-tests/*/*.sh
+tests/**/*.diff
+tests/**/*.out
+tests/**/*.php
+tests/**/*.exp
+tests/**/*.log
+tests/**/*.sh
+tests/**/*.db
+tests/**/*.mem
+tmp-php.ini