Fix Thumb-2 shared libraries

[Christophe LYON]

>>> Here's a patch I'm testing for this failure.
>> It seems OK, but I think you forgot to add a test case :-)
> 
> I think your testcase serves nicely - now that I've fixed it to test
> for correct behavior :-)
> 
I was thinking of a test involving thumb-2, as at first I thought the 
bug occurred only in thumb-2 as you mention in the subject.

> I'm going to wait for another internal test run before I commit this,
> but it looks good so far.
Good!

Christophe.