[icu-design] ICU proposal: ISO-2022-JP converter use/share Shift-JIS table

[Markus S. <mar...@gm...>]

I propose to change the ISO-2022-JP converter and its variants to use
and share the normal Shift-JIS table instead of requiring its own JIS
X 0208 conversion table. (Ticket #5797)

I also propose to hardcode the JIS X 0201 mappings as described in ticket #5880.

This will remove two .cnv files from the build and reduce the data
size by some 73kB.

Please let me know if you have any concerns, by next Tuesday oct16.

Sincerely,
markus