Add a testcase for PR ld/18176

Cherry-pick from master: 875b5b9d147d37c99a189aa95354f9bebdd64ef5
	PR ld/18176
	* ld-x86-64/pr18176.d: New file.
	* ld-x86-64/pr18176.s: Likewise.
	* ld-x86-64/pr18176.t: Likewise.
	* ld-x86-64/x86-64.exp: Run pr18176.
4 files changed