Remove a (long since) outdated prototype.
Remove a (long since) outdated prototype.

This code was back when I wanted a central function for shuffling the vectors, only when all the COP2 vector op-codes had the shuffling of VR[vt] done locally within them.  Since shuffling is now done within the COP2 dispatch before the function call table--global to all the vector instructions--there is no more need to have this prototype for a central function.  That code was probably removed over 2 years ago.

This also fixes some surviving 64-bit warnings with PIC linkage on Windows, reported by tony971, that I missed.

mupen64plus/mupen64plus-rsp-cxd4,8l/rsp,8l/rsp,8l/rsp,mupen64plus/mupen64plus-rsp-cxd4,mupen64plus/mupen64plus-rsp-cxd4