grep 2.5 build problem on QNX 6.2

[David Wolfe]

# uname -mpsr
QNX 6.2.0 x86pc x86

# config.guess
x86-pc-nto-qnx


Under QNX 6.2 (a.k.a., 'QNX Neutrino'), I get the following make error
for grep2.5:

make[3]: Entering directory `/usr/local/src/grep-2.5/lib'
source='regex.c' object='regex.o' libtool=no \
depfile='.deps/regex.Po' tmpdepfile='.deps/regex.TPo' \
depmode=gcc /bin/sh ../depcomp \
gcc -DLIBDIR=\"/usr/local/lib\" -DHAVE_CONFIG_H -I. -I. -I.. -I.. -I. -I../intl
   -g -O2 -c `test -f regex.c || echo './'`regex.c
regex.c: In function `regex_compile':
regex.c:3197: parse error before `)'

The referenced line in regex.c reads:

if (c1 < CHAR_CLASS_MAX_LENGTH )
  str[c1++] = c;


What's odd is that CHAR_CLASS_MAX_LENGTH does seem to be getting defined
properly (to 6), as shown by the output from 'gcc -E regex.c'.  So I'm a
little baffled as to why this error occurs.

Anyway, I simply hard-coded: 

if (c1 < 6 )

instead of using the macro, and this allowed me to compile and install
the app.

Wish I had advice on how to fix this, but I don't know where to begin.
(I'm happy to poke around some more if someone can tell me what to
look for.)

Regards,

- Dave