message: test: use find_exported_function in milestone2 test
diff: @@ -455,7 +455,12 @@ TEST(end_to_end, milestone2)
  "4102215320522053742154204f20546a21552055204e3602002005280228215641012157205620576a21582005"
  "20583602280c00000b000b0f0b");
  - auto instance = instantiate(parse(bin));
  + const auto module = parse(wasm);
  +
  + const auto func_idx = find_exported_function(*module, "mul256");
  + ASSERT_TRUE(func_idx);
  +
  + auto instance = instantiate(*module);
  auto& memory = *instance->memory;
  // This performs uint256 x uint256 -> uint512 multiplication.
  @@ -465,8 +470,7 @@ TEST(end_to_end, milestone2)
  // Arg2: 2^255 + 2^254 + 0xff
  memory[32] = 0xff;
  memory[63] = 0xc0;
  - // TODO: use find_exported_function
  - EXPECT_THAT(execute(*instance, 0, {64, 0, 32}), Result());
  + EXPECT_THAT(execute(*instance, *func_idx, {64, 0, 32}), Result());
  EXPECT_EQ(hex(memory.substr(64, 64)),
  "ff00000000000000000000000000000000000000000000000000000000000040"
  "8000000000000000000000000000000000000000000000000000000000000060");
  