Fix test_sys, it encoded the struct definition.

gpshead · gpshead · commit cd483f6dcffc · 2020-03-30T15:09:01.000-07:00
This is really nothing more than a change test, it needs to match the C
struct when no level23 mappings will be allocated.  An empty char[] does
not consume any C sizeof() space whereas the previous `char[1]` consumed
one alignment size worth, even when unused.
diff --git a/Lib/test/test_sys.py b/Lib/test/test_sys.py
@@ -1197,7 +1197,7 @@ class C(object): pass
         # EncodingMap
         import codecs, encodings.iso8859_3
         x = codecs.charmap_build(encodings.iso8859_3.decoding_table)
-        check(x, size('32B2iB'))
+        check(x, size('32B2i'))
         # enumerate
         check(enumerate([]), size('n3P'))
         # reverse
