MIPS linker changes for TLS HI16/LO16 relocs

[Maciej W. Rozycki]

On Tue, 2 Apr 2024, Alan Modra wrote:

> 	PR 19977
> 	* elfxx-mips.c (tls_hi16_reloc_p): New function.
> 	(mips_elf_add_lo16_rel_addend): Handle tls relocs.
> 	(_bfd_mips_elf_relocate_section): Likewise.

 And I have now committed this change as well, with a minor tweak to the 
commit heading, with an actual description added, as well as with a bunch 
of new linker test cases.

 Thank you for fixing this bug.  And as mentioned elsewhere let's leave 
HI16 list handling fix for 2.46, as that's a more complex issue to sort.

  Maciej