configure fails on every arch other than i386 and amd64

There is a check in moon's configure script to see whether the platform
compiling the plugin has the Microsoft Media Pack available to it:
CODECS_SUPPORTED="no"
CODECS_ARCH_SUPPORTED="no"
CODECS_OS_SUPPORTED="no"

case "$host" in
        i*86-*-*)
                ARCH=x86
                CODECS_ARCH_SUPPORTED="yes"
                ;;
        x86_64-*-* | amd64-*-*)
                ARCH=x64
                CODECS_ARCH_SUPPORTED="yes"
                ;;
esac
case "$host" in
    *-*-*linux*)
                OSTYPE=linux
                CODECS_OS_SUPPORTED="yes"
                ;;
esac

if test ${ARCH} = unknown; then
        { { echo "$as_me:$LINENO: error: The codecs have not been configured to
build on this architecture yet" >&5
echo "$as_me: error: The codecs have not been configured to build on this
architecture yet" >&2;}
   { (exit 1); exit 1; }; }
fi
if test ${OSTYPE} = unknown; then
        { { echo "$as_me:$LINENO: error: The codecs have not been configured to
build on this operating system yet" >&5
echo "$as_me: error: The codecs have not been configured to build on this
operating system yet" >&2;}
   { (exit 1); exit 1; }; }
fi

Unfortunately, this check causes moon to fail to build on non-x86ish
architectures, even when using --with-ffmpeg=yes.

Reproducible: Always

Steps to Reproduce:
1. Don't be on an x86 or amd64
2. Configure moonlight
Actual Results:
http://launchpadlibrarian.net/22777113/buildlog_ubuntu-jaunty-powerpc.moon_1.0-0ubuntu1_FAILEDTOBUILD.txt.gz

Expected Results:
Happy shiny compilation