[x265] multilib shared library not linking on Linux

[Steve Borho]

The new multilib builds seem to work pretty well now on Windows and Mac
but they are not currently working on Linux. The issue is that when the
assembly object files are linked into a static libx265 library,
theysomehow lose their position independent state which prevents those
static libx265 libraries from being linked into a multilib shared
library.

I've opened an email discussion about this on the cmake list but it
doesn't look like there will be an easy fix for it.

As a short-term workaround you can disable the shared library for the
"default depth" build and it will build a statically linked multilib CLI
app.

-- 
Steve Borho