This patch skips gc-sections if input relocation is incompatible with
output.
bfd/
PR ld/18160
* elflink.c (elf_gc_sweep): Skip if relocation is incompatible.
(bfd_elf_gc_sections): Likewise.
ld/testsuite/
PR ld/18160
* ld-x86-64/pr18160.d: New file.
* ld-x86-64/pr18160.s: Likewise.
* ld-x86-64/pr18160.t: Likewise.
* ld-x86-64/x86-64.exp: Run pr18160.