Fix clang build error for empty entry list placeholder

Author: TysonAndre

ext/collections/collections_deque.c

@@ -38,6 +38,8 @@
 
 #include <stdbool.h>
 
+static const zval collections_empty_entry_list[1];
+
 /* Common functionality */
 #define CONVERT_OFFSET_TO_LONG_OR_THROW(index, zv) do { \
        if (Z_TYPE_P(offset_zv) != IS_LONG) { \
@@ -108,7 +110,7 @@ static void DEBUG_ASSERT_CONSISTENT_DEQUE(const collections_deque_entries *array
 	const uint32_t capacity = collections_deque_entries_get_capacity(array);
 	ZEND_ASSERT(array->size <= capacity);
 	ZEND_ASSERT(array->offset < capacity || capacity == 0);
-	ZEND_ASSERT(array->mask == 0 || (array->circular_buffer != NULL && array->circular_buffer != empty_entry_list));
+	ZEND_ASSERT(array->mask == 0 || (array->circular_buffer != NULL && array->circular_buffer != collections_empty_entry_list));
 	ZEND_ASSERT(collections_is_valid_uint32_capacity(capacity));
 	ZEND_ASSERT(array->circular_buffer != NULL || ((array->size == 0 && array->offset == 0) || capacity == 0));
 }
@@ -193,7 +195,7 @@ static void collections_deque_entries_init_from_array(collections_deque_entries
 			i++;
 		} ZEND_HASH_FOREACH_END();
 	} else {
-		array->circular_buffer = (zval *)empty_entry_list;
+		array->circular_buffer = (zval *)collections_empty_entry_list;
 	}
 }
 
@@ -269,7 +271,7 @@ static void collections_deque_entries_copy_ctor(collections_deque_entries *to, c
 	to->mask = 0;
 	to->offset = 0;
 	if (!size) {
-		to->circular_buffer = (zval *)empty_entry_list;
+		to->circular_buffer = (zval *)collections_empty_entry_list;
 		return;
 	}
 
@@ -501,7 +503,7 @@ PHP_METHOD(Collections_Deque, __construct)
 		intern->array.offset = 0;
 		intern->array.size = 0;
 		intern->array.mask = 0;
-		intern->array.circular_buffer = (zval *)empty_entry_list;
+		intern->array.circular_buffer = (zval *)collections_empty_entry_list;
 		return;
 	}
 
@@ -629,7 +631,7 @@ PHP_METHOD(Collections_Deque, __unserialize)
 		array->offset = 0;
 		array->size = 0;
 		array->mask = 0;
-		array->circular_buffer = (zval *)empty_entry_list;
+		array->circular_buffer = (zval *)collections_empty_entry_list;
 		return;
 	}
 

ext/collections/collections_util.h

@@ -19,7 +19,6 @@
 #include "Zend/zend.h"
 
 #define COLLECTIONS_MAX_ZVAL_COLLECTION_SIZE HT_MAX_SIZE
-#define empty_entry_list ((const void*) (((uint8_t*)NULL) + 16))
 static zend_always_inline uint32_t collections_next_pow2_capacity_uint32(uint32_t nSize, uint32_t min) {
 	if (nSize < min) {
 		return min;