X86: Implement MOVQ2DQ.

src/arch/x86/isa/decoder/two_byte_opcodes.isa

@@ -951,7 +951,7 @@
                     }
                     // repe (0xF3)
                     0x4: decode OPCODE_OP_BOTTOM3 {
-                        0x6: WarnUnimpl::movq2dq_Vo_PRq();
+                        0x6: MOVQ2DQ(Vo,PRq);
                         default: UD2();
                     }
                     // operand size (0x66)

src/arch/x86/isa/insts/simd128/integer/data_transfer/move.py

@@ -82,8 +82,12 @@ def macroop MOVQ_P_XMM {
 def macroop MOVDQ2Q_MMX_XMM {
     movfp mmx, xmmlm, dataSize=8
 };
+
+def macroop MOVQ2DQ_XMM_MMX {
+    movfp xmml, mmxm, dataSize=8
+    lfpimm xmmh, 0
+};
 '''
 # MOVDQA
 # MOVDQU
-# MOVQ2DQ
 # LDDQU