Re: PowerPC64 .branch_lt address

Re: PowerPC64 .branch_lt address

On seeing PR29369 my suspicion was naturally on a recent powerpc64
change, commit 0ab80031430e.  Without a reproducer, I spent time
wondering what could have gone wrong, and while I doubt this patch
would have fixed the PR, there are some improvements that can be made
to cater for user silliness.

I also noticed that when -z relro -z now sections are created out of
order, with .got before .plt in the section headers but .got is laid
out at a higher address.  That's due to the address expression for
.branch_lt referencing SIZEOF(.got) and so calling init_os (which
creates a bfd section) for .got before the .plt section is created.
Fix that by ignoring SIZEOF in exp_init_os.  Unlike ADDR and LOADADDR
which need to reference section vma and lma respectively, SIZEOF can
and does cope with a missing bfd section by returning zero for its
size, which of course is correct.

	PR 29369
	* ldlang.c (exp_init_os): Don't create a bfd section for SIZEOF.
	* emulparams/elf64ppc.sh (OTHER_RELRO_SECTIONS_2): Revise
	.branch_lt address to take into account possible user sections
	with alignment larger than 8 bytes.