Allow self etc in eval / file scope

This fixes a regression from 16a9bc1.
Together with the recent closure related changes this should allow
all usages of self etc, while previously (in PHP 5) some things like
self::class did not work.

Author: nikic

Zend/tests/self_class_const_outside_class.phpt

@@ -1,8 +1,10 @@
 --TEST--
-Accessing self::FOO outside a class
+Accessing self::FOO in a free function
 --FILE--
 <?php
-var_dump(self::FOO);
+function test() {
+    var_dump(self::FOO);
+}
 ?>
 --EXPECTF--
 Fatal error: Cannot use "self" when no class scope is active in %s on line %d

Zend/tests/self_in_eval.phpt

@@ -0,0 +1,28 @@
+--TEST--
+self etc. can be used in eval() in a class scope
+--FILE--
+<?php
+
+class C {
+    const FOO = 1;
+    private static $bar = 2;
+    public static function f() {
+        eval(<<<'PHP'
+var_dump(self::FOO);
+var_dump(self::$bar);
+var_dump(self::class);
+var_dump(static::class);
+PHP
+        );
+    }
+}
+
+C::f();
+
+?>
+--EXPECT--
+int(1)
+int(2)
+string(1) "C"
+string(1) "C"
+

Zend/zend_compile.c

@@ -1325,6 +1325,11 @@ static inline zend_bool zend_is_scope_known() /* {{{ */
 		return 0;
 	}
 
+	if (!CG(active_op_array)->function_name) {
+		/* A file/eval will be run in the including/eval'ing scope */
+		return 0;
+	}
+
 	if (!CG(active_class_entry)) {
 		/* Not being in a scope is a known scope */
 		return 1;