Do runtime detection of SSE2 for x86 variants when necessary.
Do runtime detection of SSE2 for x86 variants when necessary.

We use inline SSE2 assembly for memory fences on x86 machines when building with gcc. Non-SSE2 machines do not need these memory barriers (in theory) and will crash if these instructions are issued.

This fixes the case where iaxclient caused program crashes on non-SSE2 x86 machines.


git-svn-id: 9ed0004971709408f906b8bdafa7f98a7bcab630@1195 f854266a-e20d-0410-a9be-8852184c940f

zlargon/iaxclient,zlargon/iaxclient,zlargon/iaxclient,zlargon/iaxclient,zlargon/iaxclient