Correct disassembly of some SSE instructions on x86-64.

Correct disassembly of some SSE instructions on x86-64.

CVTSD2SI, CVTSS2SI, CVTTSD2SI and CVTTSS2SI used to print a source
memory operand with a size indicator wrongly indicating the size of
the destination, for example "CVTTSS2SI RDX, QWORD PTR [RBP-8]".
Correct this by printing the memory reference without a size indicator
as the size of the source is implicit in the instruction. Remove an
argument type and a print function that were used only for these
instructions.