Correct test of OptionsImpl argc type (Was: Correct type for std::arr…

…ay size() result) (#9290)

The std::array API uses std::size_t for the size() nelts count.
This is a larger sized int than 'int', which causes this code
to break on Windows compilation.

Use the stdcxx type for conformance and portability.

Signed-off-by: Sunjay Bhatia <sbhatia@pivotal.io>
Signed-off-by: William A Rowe Jr <wrowe@pivotal.io>

test/server/options_impl_test.cc

@@ -253,15 +253,15 @@ TEST_F(OptionsImplTest, OptionsAreInSyncWithProto) {
 TEST_F(OptionsImplTest, OptionsFromArgv) {
   const std::array<const char*, 3> args{"envoy", "-c", "hello"};
   std::unique_ptr<OptionsImpl> options = std::make_unique<OptionsImpl>(
-      args.size(), args.data(), [](bool) { return "1"; }, spdlog::level::warn);
+      static_cast<int>(args.size()), args.data(), [](bool) { return "1"; }, spdlog::level::warn);
   // Spot check that the arguments were parsed.
   EXPECT_EQ("hello", options->configPath());
 }
 
 TEST_F(OptionsImplTest, OptionsFromArgvPrefix) {
   const std::array<const char*, 5> args{"envoy", "-c", "hello", "--admin-address-path", "goodbye"};
   std::unique_ptr<OptionsImpl> options = std::make_unique<OptionsImpl>(
-      args.size() - 2, // Pass in only a prefix of the args
+      static_cast<int>(args.size()) - 2, // Pass in only a prefix of the args
       args.data(), [](bool) { return "1"; }, spdlog::level::warn);
   EXPECT_EQ("hello", options->configPath());
   // This should still have the default value since the extra arguments are