Attempted workaround for GCC PPC EMU128 test failure, refs #3024

Add Unpredictable1 instead of literal

PiperOrigin-RevId: 908194619

Author: jan-wassenberg

hwy/tests/memory_test.cc

@@ -149,14 +149,14 @@ struct TestLoadDup128 {
     constexpr size_t N128 = 16 / sizeof(T);
     alignas(16) T lanes[N128];
     for (size_t i = 0; i < N128; ++i) {
-      lanes[i] = ConvertScalarTo<T>(1 + i);
+      lanes[i] = ConvertScalarTo<T>(hwy::Unpredictable1() + i);
     }
 
     const size_t N = Lanes(d);
     auto expected = AllocateAligned<T>(N);
     HWY_ASSERT(expected);
     for (size_t i = 0; i < N; ++i) {
-      expected[i] = ConvertScalarTo<T>(i % N128 + 1);
+      expected[i] = ConvertScalarTo<T>(i % N128 + hwy::Unpredictable1());
     }
 
     HWY_ASSERT_VEC_EQ(d, expected.get(), LoadDup128(d, lanes));