[XLA] Remove TPU-specific aliasing #ifdef which is no longer TPU-specific

PiperOrigin-RevId: 316806281
Change-Id: I6acab4ed606cc123052b539a4b2b160fffe21b5b

tensorflow/compiler/xla/tests/buffer_donation_test.cc

@@ -109,9 +109,7 @@ class BufferDonationTest : public HloTestBase {
               << "             size = " << result_root_buffer.size();
 
     // Check for expected aliasing between input and output buffers.
-    // The following aliasing pattern is only ever generated by the TPU backend
-    // at the moment.
-#if defined(XLA_TEST_BACKEND_TPU)
+#ifndef XLA_TEST_BACKEND_INTERPRETER
     for (int i = 0; i < ShapeUtil::TupleElementCount(argument_literal.shape());
          ++i) {
       const ShapeIndex index({i});