expr ... and `expr ...` return different results on QNX 4.2.5

[David Morgan]

Hi folks,

Thanks for the changes by including as_expr there is a problem with the test,
and/or another bug in QNX (I suspect).

The code:

expr a : '\(a\)'
echo $?
b=`expr a : '\(a\)'`
echo $b,$?

Gives:

a
1
a,0

The `` seem to affect the return code from the expr.

This means QNX still thinks it has a working expr.  Looks like this needs a 
different sort of test.

Once I tell QNX that it does not have a working expr (and I fix the 
CONFIG_FILES issue) then I can successfully run make.

Regards
 David