perl 3.0 patch #28 (combined patch)

perl 3.0 patch #28 (combined patch)

Certain systems, notable Ultrix, set the close-on-exec flag
by default on dup'ed file descriptors.  This is anti-social
when you're creating a new STDOUT.  The flag is now forced
off for STDIN, STDOUT and STDERR.

Some yaccs report 29 shift/reduce conflicts and 59 reduce/reduce
conflicts, while other yaccs and bison report 27 and 61.  The
Makefile now says to expect either thing.  I'm not sure if there's
a bug lurking there somewhere.

The defined(@array) and defined(%array) ended up defining
the arrays they were trying to determine the status of.  Oops.

Using the status of NSIG to determine whether <signal.h> had
been included didn't work right on Xenix.  A fix seems to be
beyond Configure at the moment, so we've got some OS dependent
#ifdefs in there.

There were some syntax errors in the new code to determine whether
it is safe to emulate rename() with unlink/link/unlink.  Obviously
heavily tested code...  :-)

Patch 27 introduced the possibility of using identifiers as
unquoted strings, but the code to warn against the use of
totally lowercase identifiers looped infinitely.

I documented that you can't interpolate $) or $| in pattern.
It was actually implied under s///, but it should have been
more explicit.

Patterns with {m} rather than {m,n} didn't work right.

Tests io.fs and op.stat had difficulties under AFS.  They now
ignore the tests in question if they think they're running under
/afs.

The shift/reduce expectation message was off for a2p's Makefile.