linux-thread.o no longer used

[Kevin Buettner]

On Dec 8,  2:36pm, Jim Blandy wrote:

> With the change I just committed below, there are no longer any users
> of linux-thread.o.  Can we delete this file?

lin-thread.[co] is another one that's no longer used.

For both of these files, it may be better to just mark them as
obsolete for a while since it's occassionally useful to be able to
refer to these old versions.  Of course if it is deleted, we can still
check out an old version of the file from the Attic, but it is
somewhat less convenient than just having the file there to look at.

Kevin