Fix concatenates and vectored bufif1, bug326.

src/V3Number.cpp

@@ -1318,6 +1318,15 @@ V3Number& V3Number::opPowS (const V3Number& lhs, const V3Number& rhs) {
     return setAllBitsX();
 }
 
+V3Number& V3Number::opBufIf1  (const V3Number& ens, const V3Number& if1s) {
+    setZero();
+    for(int bit=0; bit<this->width(); bit++) {
+	if (ens.bitIs1(bit))  { setBit(bit, if1s.bitIs(bit)); }
+	else setBit(bit,'z');
+    }
+    return *this;
+}
+
 V3Number& V3Number::opAssign (const V3Number& lhs) {
     // Note may be a width change during the assign
     setZero();