Fix PR12762 using linkonce sections in plugin bfd

[Alan Modra]

On Thu, Aug 11, 2011 at 06:18:03AM -0700, H.J. Lu wrote:
> This is the first approach I tried and failed with GCC 4.7 LTO
> tests on Linux/x86-64 since adding new sections to dummy
> LTO bfd at this stage didn't work very well.

Current mainline gcc bootstrap and regression tests look good on
powerpc.  What is peculiar about x86-64?  Can you test my patch and
let me know what fails?  I'll wait to hear back before applying.

-- 
Alan Modra
Australia Development Lab, IBM