Add EG(bailout) consistency assertion

Make sure EG(bailout) is what we expect. This will detect faulty jumps into or
out of zend_try blocks, as in 38628e8.

Closes phpGH-21667

Author: iluuu1994

Zend/zend.h

@@ -275,7 +275,9 @@ typedef size_t (*zend_write_func_t)(const char *str, size_t str_length);
 		EG(bailout) = &__bailout;								\
 		if (SETJMP(__bailout)==0) {
 #define zend_catch												\
+			ZEND_ASSERT(EG(bailout) == &__bailout);				\
 		} else {												\
+			ZEND_ASSERT(EG(bailout) == &__bailout);				\
 			EG(bailout) = __orig_bailout;
 #define zend_end_try()											\
 		}														\