x64: Fix codegen for the select instruction with v128 (#4317)

This commit fixes a bug in the previous codegen for the `select`
instruction when the operations of the `select` were of the `v128` type.
Previously teh `XmmCmove` instruction only stored an `OperandSize` of 32
or 64 for a 64 or 32-bit move, but this was also used for these 128-bit
types which meant that when used the wrong move instruction was
generated. The fix applied here is to store the whole `Type` being moved
so the 128-bit variant can be selected as well.

cranelift/codegen/src/isa/x64/lower.rs

@@ -2271,11 +2271,7 @@ fn lower_insn_to_regs<C: LowerCtx<I = Inst>>(
                 debug_assert!(ty == types::F32 || ty == types::F64);
                 emit_moves(ctx, dst, rhs, ty);
                 ctx.emit(Inst::xmm_cmove(
-                    if ty == types::F64 {
-                        OperandSize::Size64
-                    } else {
-                        OperandSize::Size32
-                    },
+                    ty,
                     cc,
                     RegMem::reg(lhs.only_reg().unwrap()),
                     dst.only_reg().unwrap(),