Link x86-64 mark-plt-1.so with --no-as-needed

Fixes
FAIL: Build mark-plt-1.so
where gcc is built with default --as-needed.

	* testsuite/ld-x86-64/x86-64.exp (Build mark-plt-1.so): Pass
	--no-as-needed.

(cherry picked from commit 60c95acd)