Cygwin updates against zsh-4.2.3.  See attached diffs:

configure.ac - check for iconv.h
             - check for libiconv() if cygwin
	     - call 'pcre-config --libs' to get LIBS if using pcre
Src/utils.c  - added if defined(HAVE_ICONV_H) to #if's which test for
               HAVE_ICONV or HAVE_LIBICONV

Notes:

Added iconv.h header to header check list.  This is really just for
completeness.  iconv() in Cygwin is really libiconv() (iconv.h does a
"#define iconv libiconv").  However the AC_CHECK_LIB() macro doesn't know
to include iconv.h.  I played with coding a custom conf test to #include
iconv.h but ran into prototype issues and decided it was simpler to just
look for the real function instead using AC_CHECK_LIB.

pcre's libs should be obtained by running pcre-config.  This isn't really
a cygwin-ism, but more of a generic pcre issue.

FIFO's in Cygwin are implemented using Windows' underlying named pipes
implementation and are somewhat buggy (like Windows, itself :).  Until
this is resolved, it makes more sense to disable their usage.  I'll
track this issue and send updates when things are working properly.

Thanks!

-- 
Peter A. Castro <doctor@fruitbat.org> or <Peter.Castro@oracle.com>
	"Cats are just autistic Dogs" -- Dr. Tony Attwood