Wrong ELF class plugin vs. gcc ld version

When building 32-bit binutils with CC="gcc -m32" CXX="g++ -m32" we can
fail the gcc ld version test due to an error attempting to load a
64-bit plugin into 32-bit ld-new.  This results in bogus errors about
"Your compiler driver ignores -B when choosing ld."

	* testsuite/lib/ld-lib.exp: Whitespace.
	(load_common_lib): Expand single use and delete this proc.
	(run_host_cmd): Use -fno-lto when getting gcc's ld version.
	Use -B for clang too.