fix agent unit tests (#994)

PHP's build system received a fix for 'out of tree' builds. This broke build of
agent's unit tests which require agent's source directory to be in the include
search path. Working agent's unit tests showed that `test_function_debug_name`
needed its expectations tweaked - closures are named differently on PHP 8.4.

agent/config.m4

@@ -239,6 +239,9 @@ if test "$PHP_NEWRELIC" = "yes"; then
   dnl Define $(PHP_CONFIG) so we can call it when building tests.
   PHP_SUBST(PHP_CONFIG)
 
+  dnl Make sure we include the source directory in the include search path.
+  PHP_ADD_INCLUDE([$abs_srcdir], [1])
+
   dnl Include the Makefile.frag, which we use to handle build time
   dnl dependencies.
   PHP_ADD_MAKEFILE_FRAGMENT

agent/tests/test_agent.c

@@ -142,7 +142,11 @@ static void test_function_debug_name(TSRMLS_D) {
   func = nr_php_zval_to_function(closure TSRMLS_CC);
   name = nr_php_function_debug_name(func);
 
+#if ZEND_MODULE_API_NO < ZEND_8_4_X_API_NO
   tlib_pass_if_str_equal("closure", "{closure} declared at -:1", name);
+#else
+  tlib_pass_if_str_equal("closure", "{closure:-:1} declared at -:1", name);
+#endif
 
   nr_php_zval_free(&closure);
   nr_free(name);