Adjust LOAD segment to generate GNU_RELRO segment

Adjust LOAD segment to generate GNU_RELRO segment

This patch fixes 2 GNU_RELRO segment bugs:

1. lang_size_sections didn't properly align base to the maximum
alignment power of sections between DATA_SEGMENT_ALIGN and
DATA_SEGMENT_RELRO_END.
2. ld failed to adjust LOAD segment to generate GNU_RELRO segment
when LOAD segment doesn't fit GNU_RELRO segment.  This is

https://sourceware.org/bugzilla/show_bug.cgi?id=14207

We "fixed" ld by not generating GNU_RELRO segment.  This patch
adjusts LOAD segment to generate GNU_RELRO segment.  It fixes
PR ld/16322 and at the same time it also fixes PR binutils/16323
since now we can adjust LOAD segment if it is too small.

bfd/

	PR ld/14207
	PR ld/16322
	PR binutils/16323
	* elf.c (_bfd_elf_map_sections_to_segments): Don't check section
	size for PT_GNU_RELRO segment.
	(assign_file_positions_for_load_sections): If PT_LOAD segment
	doesn't fit PT_GNU_RELRO segment, adjust its p_filesz and p_memsz.

ld/

	PR ld/14207
	PR ld/16322
	PR binutils/16323
	* ldlang.c (lang_size_sections): Properly align RELRO base.

ld/testsuite/

	PR ld/14207
	PR ld/16322
	PR binutils/16323
	* ld-elf/pr16322.d: New file.
	* ld-elf/pr16322.s: Likewise.

	* ld-x86-64/pr14207.d: Expect PT_GNU_RELRO segment.