Add PACKUSDW SSE4.1 support for x86

Add PACKUSDW SSE4.1 support for x86

Add handling of PACKUSDW to VEX/priv/guest_x86_toIR.c based on the
guest_amd64_toIR.c implementation. Handle Iop_QNarrowBin32Sto16Ux8
using h_generic_calc_QNarrowBin32Sto16Ux8 in VEX/priv/host_x86_isel.c.

Move test_PACKUSDW from none/tests/amd64/sse4-64.c to
none/tests/sse4-common.h and add the same test to
none/tests/x86/sse4-x86.c with new PACKUSDW output in stdout.exp.

https://bugs.kde.org/show_bug.cgi?id=517144