re/charset.t: Allow to work on EBCDIC

This just converts the hard-coded character numbers to native, so will
work on any platform.
hints/os390.sh: Suppress bogus compiler message
regcomp.c: Fix bug in EBCDIC

The POSIXA and NPOSIXA regnodes need to set the bits on only the ASCII
code points, but under EBCDIC those code points are 0-127.
XXX: regen/regcharclass.pl: Temp for testing
XXX Temp add debug statements
XXX charnames.t: Make more EBCDIC friendly

Why need utf8::unicode_to_native
XXX make various things more EBCDIC friendly

Adds trailing white space errors
Need to know what to do about ^A meaning 0x1, and M-foo meaning meta
regen/mk_PL_charclass.pl: XXX Make EBCDIC friendly

need more of a commit message
XXX makedepend.SH: Why does 255 work and 250 not?
t/test.pl: Add comment about EBCDIC