Allow copy relocations with pie links

[Cary Coutant]

> x86 doesn't have PC-relative data access.  x86 needs
> to use GOT for all data access in PIE unless run-time
> text relocation is allowed.  Normally x86 shouldn't have
> copy relocation in PIE.

Right. With Sri's test case, we get an absolute R_386_32 relocation
for the access, and the DT_TEXTREL flag is set in the PIE binary
because of the text relocation. There is no COPY relocation. Since we
had a path in the code to check for copy relocs for the PC-relative
relocations, I think it makes sense to adjust the test there, though.

-cary