Fix fastsearch for UCS2 and UCS4
* If needle is 0, try (p[0] >> 16) & 0xff for UCS4
* Disable fastsearch_memchr_1char() if needle is zero for UCS2 and UCS4
diff --git a/Objects/stringlib/asciilib.h b/Objects/stringlib/asciilib.h
index 935a9c7..bfd5d75a 100644
--- a/Objects/stringlib/asciilib.h
+++ b/Objects/stringlib/asciilib.h
@@ -6,6 +6,7 @@
#define FASTSEARCH asciilib_fastsearch
#define STRINGLIB(F) asciilib_##F
#define STRINGLIB_OBJECT PyUnicodeObject
+#define STRINGLIB_SIZEOF_CHAR 1
#define STRINGLIB_CHAR Py_UCS1
#define STRINGLIB_TYPE_NAME "unicode"
#define STRINGLIB_PARSE_CODE "U"