[hlo_evaluator] Don't create blank, zero-populated Literals for tuples

When evaluating Tuple(), create a blank Literal for the destination that is populated with
kUndetermined.

We already copy in all known leaves, so all this does is avoid us creating blank leaf Pieces,
which is incredibly important when dealing with large programs pre-sharding. Also note that
we'd instantaneously throw the blank pieces all away...

PiperOrigin-RevId: 571532410

third_party/xla/xla/hlo/evaluator/hlo_evaluator.cc

@@ -1582,15 +1582,28 @@ Status HloEvaluator::HandleTuple(const HloInstruction* tuple) {
     }
   }
 
+  // Inline part of LiteralUtil::MakeTuple() that avoids creating the leaf
+  // buffers; these buffers can be extremely large.
+  std::vector<const Shape*> element_shapes;
+  element_shapes.reserve(operand_literals.size());
+  for (const auto* element : operand_literals) {
+    element_shapes.push_back(&element->shape());
+  }
+  Literal new_result = Literal::CreateFromShapeWithUndeterminedLeafArrays(
+      ShapeUtil::MakeTupleShapeWithPtrs(element_shapes));
+  for (int i = 0, end = operand_literals.size(); i < end; ++i) {
+    TF_RETURN_IF_ERROR(
+        new_result.CopyFrom(*operand_literals[i], /*dest_shape_index=*/{i}));
+  }
+
   if (evaluated_.contains(tuple)) {
-    Literal new_result = LiteralUtil::MakeTuple(operand_literals);
     CHECK(new_result.IsDetermined(visitor_shape_index_));
     TF_RETURN_IF_ERROR(
-        evaluated_[tuple].CopyFrom(new_result,
+        evaluated_[tuple].CopyFrom(std::move(new_result),
                                    /*dest_shape_index=*/visitor_shape_index_,
                                    /*src_shape_index=*/visitor_shape_index_));
   } else {
-    evaluated_[tuple] = LiteralUtil::MakeTuple(operand_literals);
+    evaluated_[tuple] = std::move(new_result);
   }
   return OkStatus();
 }