xxhash-0.8.3 renamed struct member memsize to bufferedSize.

Index: ext/hash/hash_xxhash.c
--- ext/hash/hash_xxhash.c.orig
+++ ext/hash/hash_xxhash.c
@@ -79,7 +79,7 @@ static int php_hash_xxh32_unserialize(
 	int r = FAILURE;
 	if (magic == PHP_HASH_SERIALIZE_MAGIC_SPEC
 		&& (r = php_hash_unserialize_spec(hash, zv, PHP_XXH32_SPEC)) == SUCCESS
-		&& ctx->s.memsize < 16) {
+		&& ctx->s.bufferedSize < 16) {
 		return SUCCESS;
 	} else {
 		return r != SUCCESS ? r : -2000;
@@ -227,7 +227,7 @@ static int php_hash_xxh64_unserialize(
 	int r = FAILURE;
 	if (magic == PHP_HASH_SERIALIZE_MAGIC_SPEC
 		&& (r = php_hash_unserialize_spec(hash, zv, PHP_XXH64_SPEC)) == SUCCESS
-		&& ctx->s.memsize < 32) {
+		&& ctx->s.bufferedSize < 32) {
 		return SUCCESS;
 	} else {
 		return r != SUCCESS ? r : -2000;
