The pcre2test utility needs quite a few changes to accommodate this.
It is simpler to add a new mode to it, than to make it fully
EBCDIC-native. On an ASCII system, pcre2test performs ASCII I/O, but
tranlates the input when passing it to the fully-EBCDIC-supporting
library.
Use a similar syntax to pcre2test to set a per pattern locale, and
teach pcre2test to recognize the modifier as perl compatible.
While at it, update tests and fix a recent regresion that wasn't
covered by them.
* pcre2test: tighten \N{U+hh...} support
When \N{U+hh...} was added it was meant to support all unicode
characters that can be encoded by pcre2test and Perl, but its
use outside what is officially considered valid can be confusing
so print a warning for those cases.
* perltest: add support for hex modifier
The use of \xhh can be ambiguous when used together with the utf modifier,
so allow for describing code points individually in the pattern using hex,
with the same syntax that is already supported by pcre2test.
When providing escaped values in the subject, the syntax can be
ambiguous, so add support for a new escape that is always meant
to refer to a Unicode character and that is already supported
by the library in utf mode.
While at it, refactor the code to support octal escapes and fix
bugs with overlong numbers, as well to simplify the logic that
decides if an escape is encoded as a code unit or as an Unicode
character, that could require multiple code units.
Eventhough it is documented that invalid escapes will be reported,
the code would fallback in that case and result in a NUL being
generated whenever an incompete \x{ escape was being parsed.
Refactor the code to report the error instead and fix the logic used
for overlong numbers so that the truncation doesn't result in an
unexpected value being used.
There was an old (from PCRE 4.0) test that was affected but which is
no longer relevant, because it could only be triggered with invalid
UTF (which isn't supported), and that was therefore removed as a
result.
Additionally, it was found that the same syntax error was affecting
perltest so correct that as well by reporting syntax errors in the
subject lines.
While at it update related documentation for Perl's compatibility.
