More EBCDIC tweaks:

More EBCDIC tweaks:
 - one more swash issue &~(0xA0-1) did not do the right thing,
   for UTF-EBCDIC where &~(0x80-1) does for UTF-8.
 - add "use re 'asciirange'" to make [!-~] etc. work
   use it in MIME::QuotedPrint and t/op/regexp.t and t/op/pat.t
 - Choose a key for t/op/each.t test which gets encoded.
 - Skip utf8decode if this is UTF-EBCDIC.

p4raw-id: //depot/perlio@9400