'RELENG_6_0_0_RELEASE'.

This commit was manufactured to restore the state of the 6.0-RELEASE image.

include it in all cases.

multibyte character support:
- In CHadd(), avoid writing past the end of the character set bitmap when
  the opposite-case counterpart of wide characters with values less than
  NC have values greater than or equal to NC.
- In CHaddtype(), fix a braino that caused alphabetic characters to be
  added to all character classes! (but only with REG_ICASE)

PR:		71367

idea is that we perform multibyte->wide character conversion while parsing
and compiling, then convert byte sequences to wide characters when they're
needed for comparison and stepping through the string during execution.

As with tr(1), the main complication is to efficiently represent sets of
characters in bracket expressions. The old bitmap representation is replaced
by a bitmap for the first 256 characters combined with a vector of individual
wide characters, a vector of character ranges (for [A-Z] etc.), and a vector
of character classes (for [[:alpha:]] etc.).

One other point of interest is that although the Boyer-Moore algorithm had
to be disabled in the general multibyte case, it is still enabled for UTF-8
because of its self-synchronizing nature. This greatly speeds up matching
by reducing the number of multibyte conversions that need to be done.

unused character category calculations.

Only warnings that could be fixed without changing the generated object
code and without restructuring the source code have been handled.

Reviewed by:	/sbin/md5

I believe have made all of libc .c's as consistent as possible.