ld: Always call elf_backend_output_arch_local_syms

ld: Always call elf_backend_output_arch_local_syms

Always call elf_backend_output_arch_local_syms since only the backend
knows if elf_backend_output_arch_local_syms is needed when all symbols
are striped.  elf_backend_output_arch_local_syms is defined only for
x86, ARM and AARCH64.  On x86, elf_backend_output_arch_local_syms must
be called to handle local IFUNC symbols even if all symbols are striped.
Update ARM and AARCH64 to skip elf_backend_output_arch_local_syms when
symbols aren't needed.

bfd/

	PR ld/29797
	* elf32-arm.c (elf32_arm_output_arch_local_syms): Skip if symbols
	aren't needed.
	* elfnn-aarch64.c (elfNN_aarch64_output_arch_local_syms):
	Likewise.
	* elflink.c (bfd_elf_final_link): Always call
	elf_backend_output_arch_local_syms if available.

ld/

	PR ld/29797
	* testsuite/ld-elf/linux-x86.exp: Run PR ld/29797 test.
	* testsuite/ld-elf/pr29797.c: New file.