Tests: Some tests in [41722] were using newer PHPUnit features.

`test_cache` used PHPUnit's object mocking to test some internal behaviour in `Plural_Forms`, but made use of the `willReturn()` method, which was introduced in PHPUnit 4.0 as shorthand for `will($this->returnValue())`. Fixed by switching to the longer form.

Several tests used the `@expectedException` directive to catch generic `Exception` exceptions, which was added in PHPUnit 3.7. Fixed by changing to an explicit `try` / `catch` test.

See #41562.


Built from https://develop.svn.wordpress.org/trunk@41725


git-svn-id: http://core.svn.wordpress.org/trunk@41559 1a063a9b-81f0-0310-95a4-ce76da25c4cd

wp-includes/version.php

@@ -4,7 +4,7 @@
  *
  * @global string $wp_version
  */
-$wp_version = '4.9-alpha-41724';
+$wp_version = '4.9-alpha-41725';
 
 /**
  * Holds the WordPress DB revision, increments when changes are made to the WordPress DB schema.