PATCH: PR gold/16945: Executable with -fpie and -mcmodel=large gives segfault on start

[Cary Coutant]

> 2014-05-15  H.J. Lu  <hongjiu.lu@intel.com>
>
>         PR gold/16945
>         * x86_64.cc (Target_x86_64::Relocate::relocate): Use signed int
>         for got_offset.  Properly get GOT address for R_X86_64_PLTOFF64.

(Sorry, just back from vacation.)

This is OK. Thanks!

-cary