multiple destinations in charset mapping files

[YAMAMOTO Mitsuharu]

I noticed that some charset mapping files such as
etc/charsets/symbol.map contain entries where the same source is
mapped to multiple destinations, and the latter one is preferred in
decoding in such cases.

  0x20 0x0020
  0x20 0x00A0

  (decode-char 'symbol #x20) -> 160

But at least for symbol.map, it seems to be more natural to prefer the
former entry (e.g., SPACE vs. NO-BRAKE SPACE, GREEK CAPITAL LETTER
DELTA vs. INCREMENT).  WDYT?

                                     YAMAMOTO Mitsuharu
                                address@hidden