Patch to fix thread support for Solaris x86

[Michael Snyder]

Jim Kingdon wrote:
> 
> > This patch fixes thread support for Solaris x86 platforms.
> 
> Looks like a straightforward bug fix.
> 
> Maintainer, as with the other Solaris x86 patch, currently unknown.  I
> like Kevin Buettner's suggestion of appointing a generic x86
> maintainer, if we can find a victim.

This is a sol-thread issue and relates directly to the 
thread work I was doing recently.  I'll approve it pro tem, 
and look at it more closely when I get back to that work.

Michael