Don't cast function pointers to void* (v64/v128/v256 unit tests)

Casting function pointers to void* is undefined or illegal (depending
on C/C++ dialect) and should be avoided.  Data and code could reside
in different memory.  In theory function pointers could be 64 bit and
data pointers could be 32 bit, so conversion to and from void* could
change the value.

Change-Id: Ibb70e35f21dc307cb236aecd001e15a8a8d7f9ea
1 file changed