[MIPS][MSA] Invert operand order of ILVOD

The result was <y[1], x[1]> where it should be <x[1], y[1]>.

This affects the result of vector shuffles:

    %result = shufflevector <4 x i32> %x, <4 x i32> %y,
              <4 x 132> <i32 1, i32 5, i32 3, i32 7>

The result is <%y[1], %x[1], %y[3], %x[3]>, where it should be
<%x[1], %y[1], %x[3], %y[3]>.

Author: Cyanoxygen

llvm/lib/Target/Mips/MipsSEISelLowering.cpp

@@ -2736,7 +2736,7 @@ static SDValue lowerVECTOR_SHUFFLE_ILVOD(SDValue Op, EVT ResTy,
   else
     return SDValue();
 
-  return DAG.getNode(MipsISD::ILVOD, SDLoc(Op), ResTy, Wt, Ws);
+  return DAG.getNode(MipsISD::ILVOD, SDLoc(Op), ResTy, Ws, Wt);
 }
 
 // Lower VECTOR_SHUFFLE into ILVR (if possible).