message: [XLA] Fix britle CPU test.
  Relies on a specific ordering of two constants in the IR.
  Also add HLO verification to the test's modules while we're here.
diff: @@ -63,7 +63,7 @@ CHECK-NOT: private constant [48 x i8]
  )";
  TF_ASSERT_OK_AND_ASSIGN(std::unique_ptr<HloModule> module,
  - ParseHloString(hlo_text));
  + ParseAndReturnVerifiedModule(hlo_text));
  CpuAotCompilationOptions options{
  /*triple=*/"x86_64-pc-linux", /*cpu_name=*/"", /*features=*/"",
  @@ -104,14 +104,14 @@ ENTRY main {
  )";
  string filecheck_pattern = R"(
  -CHECK: private constant [4 x i8]
  -CHECK: private constant [8 x i8]
  +CHECK-DAG: private constant [4 x i8]
  +CHECK-DAG: private constant [8 x i8]
  CHECK-NOT: private constant [4 x i8]
  CHECK-NOT: private constant [8 x i8]
  )";
  TF_ASSERT_OK_AND_ASSIGN(std::unique_ptr<HloModule> module,
  - ParseHloString(hlo_text));
  + ParseAndReturnVerifiedModule(hlo_text));
  CpuAotCompilationOptions options{
  /*triple=*/"x86_64-pc-linux", /*cpu_name=*/"", /*features=*/"",
  