Patch: fix alsa configury for systems with multilibs

[Tom Tromey]

>>>>> "Anthony" == Anthony Green <green@redhat.com> writes:

Anthony> It's not enough to test that the alsa headers exist.  We also
Anthony> need to make sure the libraries are there.  This was a
Anthony> problem for x86-64 linux.
Anthony> Ok for everywhere?

We talked on irc, but just for the record -- yes please, especially
the 4.1 branch.

Tom