Fix recursive generator in msvc (#58)

* Slightly change recursive_generator_tests to evade MS bug

See https://developercommunity.visualstudio.com/t/MSVC-generates-segfaulting-code-for-coro/10074712#T-ND10094725

Author: andreasbuhr

test/recursive_generator_tests.cpp

@@ -247,16 +247,6 @@ TEST_CASE("exception thrown from recursive call can be caught by caller")
 
 TEST_CASE("exceptions thrown from nested call can be caught by caller")
 {
-#if _MSC_VER >= 1929 && _MSVC_LANG == 202002L
-/*
- * Crashes. Known bug, reported in
- * https://github.com/andreasbuhr/cppcoro/issues/53
- * and
- * https://developercommunity.visualstudio.com/t/MSVC-generates-segfaulting-code-for-coro/10074712
- */
-	return;
-#endif
-
 	class SomeException : public std::exception {};
 
 	auto f = [](std::uint32_t depth, auto&& f) -> recursive_generator<std::uint32_t>
@@ -271,7 +261,8 @@ TEST_CASE("exceptions thrown from nested call can be caught by caller")
 
 			try
 			{
-				co_yield f(4, f);
+				auto next_generator = f(4, f);
+				co_yield next_generator;
 			}
 			catch (SomeException)
 			{
@@ -286,7 +277,8 @@ TEST_CASE("exceptions thrown from nested call can be caught by caller")
 			bool caught = false;
 			try
 			{
-				co_yield f(3, f);
+				auto next_generator = f(3, f);
+				co_yield next_generator;
 			}
 			catch (SomeException)
 			{
@@ -301,8 +293,10 @@ TEST_CASE("exceptions thrown from nested call can be caught by caller")
 		else
 		{
 			co_yield 1;
-			co_yield f(2, f);
-			co_yield f(3, f);
+			auto next_generator = f(2, f);
+			co_yield next_generator;
+			auto next_generator2 = f(3, f);
+			co_yield next_generator2;
 		}
 	};