cp5022x.el adds supprot for encodings with platform dependent characters
used in Microsoft Windows.  It defines CP50220, CP50221, CP50222, and
CP51932.  Specifications on Emacsen are as follows:

CP51932 (Microsoft euc-jp)
Type: iso-2022 (variant of ISO-2022)
Initial designations:
  G0 -- ascii:ASCII (ISO646 IRV)
  G1 -- japanese-jisx0208:JISX0208.1983/1990 Japanese Kanji: ISO-IR-87
  G2 -- katakana-jisx0201:Katakana Part of JISX0201.1976
  G3 -- never used

CP50220 (Microsoft iso-2022-jp for mail)
Type: iso-2022 (variant of ISO-2022)
Initial designations:
  G0 -- ascii:ASCII (ISO646 IRV), and also used by the following:
        japanese-jisx0208-1978:JISX0208.1978 Japanese Kanji
		(so called "old JIS"): ISO-IR-42
        japanese-jisx0208:JISX0208.1983/1990 Japanese Kanji: ISO-IR-87
        latin-jisx0201:Roman Part of JISX0201.1976
        katakana-jisx0201:Katakana Part of JISX0201.1976
  G1 -- never used
  G2 -- never used
  G3 -- never used