ensures that the symbols in the compiled XULRunner are exported for clients
like swt to link to. It's quite possible that the builder assumed
this value if --enable-application=xulrunner was specified, since xulrunners
should always be linkable. The important thing is to ensure that
it is in fact xulrunner that has been compiled (various different apps
can be built from their same source tree), and that --enable-optimize
is not specified.
As a side note, mozilla has been building 64-bit xulrunners
on a nightly basis for the last couple of versions, see http://ftp.mozilla.org/pub/mozilla.org/xulrunner/nightly/latest-mozilla-1.9.1/
and ...-1.9.2. I think these don't show up with their final releases
because they're "unsupported", but are built nightly for sanity
purposes, since the linux distros ultimately will be building and supporting
them in 64-bit form. As an experiment you could try http://ftp.mozilla.org/pub/mozilla.org/xulrunner/nightly/latest-mozilla-1.9.1/xulrunner-188.8.131.52pre.en-US.linux-x86_64.tar.bz2
since it is likely > 99% identical to their 184.108.40.206 release (I know
I advised against using "pre" releases in general, but this one
should be fine).