Remove TODO about extra move

Author: elliottt

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

@@ -3090,9 +3090,6 @@
             ;; Convert the packed float to packed doubleword.
             (dst Xmm (x64_cvttps2dq $F32X4 dst))
 
-            ;; TODO: regalloc2 introduces a useless move here, is that
-            ;; acceptable?
-
             ;; Set top bit only if < 0
             (tmp Xmm (x64_pand dst tmp))
             (tmp Xmm (x64_psrad tmp (RegMemImm.Imm 31))))