Update __cpp_lib_coroutine. (#1204)

stl/inc/yvals_core.h

@@ -172,7 +172,6 @@
 //     (partially implemented)
 // P0898R3 Standard Library Concepts
 // P0912R5 Library Support For Coroutines
-//     (partially implemented, missing noop coroutines)
 // P0919R3 Heterogeneous Lookup For Unordered Containers
 // P0966R1 string::reserve() Should Not Shrink
 // P1001R2 execution::unseq
@@ -1169,8 +1168,12 @@
 #define __cpp_lib_constexpr_tuple       201811L
 #define __cpp_lib_constexpr_utility     201811L
 
-#ifdef __cpp_impl_coroutine // TRANSITION, VS 2019 16.8 Preview 3
-#define __cpp_lib_coroutine 197000L
+#ifdef __cpp_impl_coroutine // TRANSITION, Clang and EDG coroutine support
+#if __cpp_impl_coroutine >= 201902L
+#define __cpp_lib_coroutine 201902L
+#else // ^^^ __cpp_impl_coroutine >= 201902L ^^^ / vvv __cpp_impl_coroutine < 201902L vvv
+#define __cpp_lib_coroutine 197000L // TRANSITION, VS 2019 16.8 Preview 4
+#endif // ^^^ __cpp_impl_coroutine < 201902L ^^^
 #endif // __cpp_impl_coroutine
 
 #define __cpp_lib_destroying_delete            201806L

tests/std/tests/VSO_0157762_feature_test_macros/test.cpp

@@ -481,6 +481,25 @@ STATIC_ASSERT(__cpp_lib_constexpr_utility == 201811L);
 #endif
 #endif
 
+#if _HAS_CXX20 && defined(__cpp_impl_coroutine) // TRANSITION, Clang and EDG coroutine support
+#if __cpp_impl_coroutine >= 201902L
+#define ExpectedCppLibCoroutine 201902L
+#else
+#define ExpectedCppLibCoroutine 197000L // TRANSITION, VS 2019 16.8 Preview 4
+#endif
+#ifndef __cpp_lib_coroutine
+#error __cpp_lib_coroutine is not defined
+#elif __cpp_lib_coroutine != ExpectedCppLibCoroutine
+#error __cpp_lib_coroutine is not ExpectedCppLibCoroutine
+#else
+STATIC_ASSERT(__cpp_lib_coroutine == ExpectedCppLibCoroutine);
+#endif
+#else
+#ifdef __cpp_lib_coroutine
+#error __cpp_lib_coroutine is defined
+#endif
+#endif
+
 #if _HAS_CXX20
 #ifndef __cpp_lib_destroying_delete
 #error __cpp_lib_destroying_delete is not defined