Set SHF_INFO_LINK bit for SHT_REL/SHT_RELA sections

Set SHF_INFO_LINK bit for SHT_REL/SHT_RELA sections

It is a good pratice to set the SHF_INFO_LINK bit when the sh_info field
represents a section header index.

bfd/

	PR binutils/16317
	* elf.c (assign_section_numbers): Set the SHF_INFO_LINK bit for
	SHT_REL/SHT_RELA sections when setting the sh_info field.

binutils/testsuite/

	PR binutils/16317
	* binutils-all/readelf.s: Updated.
	* binutils-all/readelf.s-64: Likewise.

ld/testsuite/

	PR binutils/16317
	* ld-elf/linkinfo1.s: New file.
	* ld-elf/linkinfo1a.d: Likewise.
	* ld-elf/linkinfo1b.d: Likewise.