Support assignments of multidimensional slices, bug170

src/V3Expand.cpp

@@ -240,6 +240,7 @@ private:
     }
     bool expandWide (AstNodeAssign* nodep, AstArraySel* rhsp) {
 	UINFO(8,"    Wordize ASSIGN(ARRAYSEL) "<<nodep<<endl);
+	if (rhsp->length()!=1) nodep->v3fatalSrc("ArraySel with length!=1 should have been removed in V3Slice");
 	for (int w=0; w<nodep->widthWords(); w++) {
 	    addWordAssign(nodep, w, newAstWordSelClone (rhsp, w));
 	}