message: test: create function Imports with explicitly instantiated FuncIdx
diff: @@ -11,7 +11,7 @@ TEST(instantiate, imported_functions)
  {
  Module module;
  module.typesec.emplace_back(FuncType{{ValType::i32}, {ValType::i32}});
  - module.importsec.emplace_back(Import{"mod", "foo", ExternalKind::Function, {0}});
  + module.importsec.emplace_back(Import{"mod", "foo", ExternalKind::Function, {FuncIdx{0}}});
  auto host_foo = [](Instance&, std::vector<uint64_t>) -> execution_result { return {true, {}}; };
  auto instance = instantiate(module, {{host_foo, module.typesec[0]}});
  @@ -29,8 +29,8 @@ TEST(instantiate, imported_functions_multiple)
  Module module;
  module.typesec.emplace_back(FuncType{{ValType::i32}, {ValType::i32}});
  module.typesec.emplace_back(FuncType{{}, {}});
  - module.importsec.emplace_back(Import{"mod", "foo1", ExternalKind::Function, {0}});
  - module.importsec.emplace_back(Import{"mod", "foo2", ExternalKind::Function, {1}});
  + module.importsec.emplace_back(Import{"mod", "foo1", ExternalKind::Function, {FuncIdx{0}}});
  + module.importsec.emplace_back(Import{"mod", "foo2", ExternalKind::Function, {FuncIdx{1}}});
  auto host_foo1 = [](Instance&, std::vector<uint64_t>) -> execution_result {
  return {true, {0}};
  @@ -56,7 +56,7 @@ TEST(instantiate, imported_functions_not_enough)
  {
  Module module;
  module.typesec.emplace_back(FuncType{{ValType::i32}, {ValType::i32}});
  - module.importsec.emplace_back(Import{"mod", "foo", ExternalKind::Function, {0}});
  + module.importsec.emplace_back(Import{"mod", "foo", ExternalKind::Function, {FuncIdx{0}}});
  EXPECT_THROW_MESSAGE(instantiate(module, {}), instantiate_error,
  "Module requires 1 imported functions, 0 provided");
  @@ -66,7 +66,7 @@ TEST(instantiate, imported_function_wrong_type)
  {
  Module module;
  module.typesec.emplace_back(FuncType{{ValType::i32}, {ValType::i32}});
  - module.importsec.emplace_back(Import{"mod", "foo", ExternalKind::Function, {0}});
  + module.importsec.emplace_back(Import{"mod", "foo", ExternalKind::Function, {FuncIdx{0}}});
  auto host_foo = [](Instance&, std::vector<uint64_t>) -> execution_result { return {true, {}}; };
  const auto host_foo_type = FuncType{{}, {}};
  