ld: Add PR ld/25593 tests

	PR ld/25593
	* testsuite/ld-plugin/lto.exp: Run PR ld/25593 tests.
	* testsuite/ld-plugin/pr25593.d: New file.
	* testsuite/ld-plugin/pr25593a-1.c: Likewise.
	* testsuite/ld-plugin/pr25593a-2.c: Likewise.
	* testsuite/ld-plugin/pr25593b.c: Likewise.
	* testsuite/ld-plugin/pr25593c.c: Likewise.
	* testsuite/ld-plugin/pr25593d.c: Likewise.
	* testsuite/ld-plugin/pr25593e.c: Likewise.