* transcode_data_one_byte: slightly optimized
* transcode_data_japanese: new data file for EUC-JP and SHIFT_JIS
(not yet optimized; tests to follow; data from
http://nkf.sourceforge.jp/ucm/{SJIS|eucJP}-nkf.ucm)
* common.mk, transcode.c: Adjusted for transcode_data_japanese
git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@14472 b2dd03c8-39d4-4d8f-98ff-823fe69b080e