Fix relro strip test for MIPS

[H.J. Lu]

On Wed, Sep 19, 2007 at 12:05:54PM -0400, Daniel Jacobowitz wrote:
> There are two unique things about MIPS which conspire to fail the
> ld -z relro -shared tests (which test that objcopy and strip do not
> change the binary).  One is that .dynamic is writable and there is no
> .got.plt section, so a typical shared library has no PT_GNU_RELRO;
> it gets added and then converted to PT_NULL.  The other is that it

We shouldn't generate a PT_NULL segment when PT_GNU_RELRO is unused.
X86 linkers should handle it correctly.

> adds a second PT_NULL program header for prelinker support.

That may be a MIPS specific problem since PT_NULL is special
for MIPS.

> These combine to produce an input file with two PT_NULL segments.
> There's a FIXME in copy_elf_program_header above some code which
> seems clearly wrong for this case.
> 

H.J.