Integrate perlio:

Integrate perlio:

[  9186]
MANIFEST addition :-(

[  9185]
Infrastructure to use UTF-EBCDIC rather than UTF-8 as the internal
encoding on EBCDIC platforms. This has property that U+0000..U+009F i.e.
a superset of ASCII are invariant under the encoding. This is EBCDIC
friendly as an encoded string can be looked at as being EBCDIC by lexer
sprintf("0",...) etc. in same manner that a UTF-8 string be considered
ASCII on ASCII machines.
- re-arrange utf8.h to get ASCII specific vs Unicode generic bits
seperate.
- Add some more macros to comprehend different shift amounts and
possible swizzle in UTF-EBCDIC vs UTF-8. Change utf8.c to use them.
- add utfebcdic.h which provides UTF-EBCDIC versions of the macros,
and conditionally #include it.
EBCDIC build as yet untested.  ASCII still fails the one test.

[  9184]
Minor naming change UTF8_IS_ASCII => UTF8_IS_INVARIANT

p4raw-link: @9186 on //depot/perlio: 57ce1777e628f108f670a828f77ce6475bb81e32
p4raw-link: @9185 on //depot/perlio: 1d72bdf6104ef56ab17c3abedf522be0125851c7
p4raw-link: @9184 on //depot/perlio: d742c382eed38a7010c93d369ad6896d826c21d6

p4raw-id: //depot/perl@9188