Resolve size relocation with copy relocation

Resolve size relocation with copy relocation

We can resolve size relocation against symbol which needs copy relocation
when building executable.

bfd/

	PR ld/20550
	* elf64-x86-64.c (elf_x86_64_relocate_section): Resolve size
	relocation with copy relocation when building executable.

ld/

	PR ld/20550
	* testsuite/ld-x86-64/pr20550a.s: New file.
	* testsuite/ld-x86-64/pr20550b.s: Likewise.
	* testsuite/ld-x86-64/x86-64.exp (x86_64tests): Add tests for
	PR ld/20550.