SF patch# 1761465 by Jeffrey Yasskin.
Fix test_aepack and test_applesingle.
diff --git a/Lib/plat-mac/Carbon/AppleEvents.py b/Lib/plat-mac/Carbon/AppleEvents.py
index e23c079..33ee3b3 100644
--- a/Lib/plat-mac/Carbon/AppleEvents.py
+++ b/Lib/plat-mac/Carbon/AppleEvents.py
@@ -1,6 +1,6 @@
 # Generated from 'AEDataModel.h'
 
-def FOUR_CHAR_CODE(x): return x
+def FOUR_CHAR_CODE(x): return bytes(x)
 typeBoolean = FOUR_CHAR_CODE('bool')
 typeChar = FOUR_CHAR_CODE('TEXT')
 typeSInt16 = FOUR_CHAR_CODE('shor')