libstdc++.exp (libstdc++_init): Use the same flags for remote host testing we use...

libstdc++.exp (libstdc++_init): Use the same flags for remote host testing we use for local host testing.

	* testsuite/lib/libstdc++.exp (libstdc++_init): Use the same flags
	for remote host testing we use for local host testing.  Copy all
	testsuite headers to the remote host
	(v3_target_compile_as_c): Use remote_exec, not just exec.

From-SVN: r124051