message: [vm_runtime] some minor test cleanup
  Fix a TODO and make the function accept borrowed strings too.
diff: @@ -434,11 +434,9 @@ fn test_multi_level_cache_write_back() {
  assert_eq!(func2_ref.code_definition(), vec![Bytecode::Ret].as_slice());
  }
  -// TODO: What this function does is way beyond its name suggests.
  -// Fix it and code depending on it.
  -fn parse_modules(s: String) -> Vec<CompiledModule> {
  +fn parse_and_compile_modules(s: impl AsRef<str>) -> Vec<CompiledModule> {
  let address = AccountAddress::default();
  - let parsed_program = parse_program(&s).unwrap();
  + let parsed_program = parse_program(s.as_ref()).unwrap();
  let compiled_program = compiler::compile_program(&address, &parsed_program, &[]).unwrap();
  compiled_program.modules
  @@ -449,8 +447,7 @@ fn test_same_module_struct_resolution() {
  let allocator = Arena::new();
  let vm_cache = VMModuleCache::new(&allocator);
  - let code = String::from(
  - "
  + let code = "
  modules:
  module M1 {
  struct X {}
  @@ -460,10 +457,9 @@ fn test_same_module_struct_resolution() {
  main() {
  return;
  }
  - ",
  - );
  + ";
  - let module = parse_modules(code);
  + let module = parse_and_compile_modules(code);
  let fetcher = FakeFetcher::new(module);
  let block_cache = BlockModuleCache::new(&vm_cache, fetcher);
  {
  @@ -511,7 +507,7 @@ fn test_multi_module_struct_resolution() {
  hex::encode(AccountAddress::default())
  );
  - let module = parse_modules(code);
  + let module = parse_and_compile_modules(&code);
  let fetcher = FakeFetcher::new(module);
  let block_cache = BlockModuleCache::new(&vm_cache, fetcher);
  {
  @@ -539,8 +535,7 @@ fn test_field_offset_resolution() {
  let allocator = Arena::new();
  let vm_cache = VMModuleCache::new(&allocator);
  - let code = String::from(
  - "
  + let code = "
  modules:
  module M1 {
  struct X { f: u64, g: bool}
  @@ -550,10 +545,9 @@ fn test_field_offset_resolution() {
  main() {
  return;
  }
  - ",
  - );
  + ";
  - let module = parse_modules(code);
  + let module = parse_and_compile_modules(code);
  let fetcher = FakeFetcher::new(module);
  let block_cache = BlockModuleCache::new(&vm_cache, fetcher);
  {
  