Merge commit '4d0786a817ae' from apple/main into swift/next

Author: git apple-llvm automerger

clang/lib/Headers/__clang_hip_cmath.h

@@ -626,6 +626,13 @@ _GLIBCXX_END_NAMESPACE_VERSION
 
 // Define device-side math functions from <ymath.h> on MSVC.
 #if defined(_MSC_VER)
+
+// Before VS2019, `<ymath.h>` is also included in `<limits>` and other headers.
+// But, from VS2019, it's only included in `<complex>`. Need to include
+// `<ymath.h>` here to ensure C functions declared there won't be markded as
+// `__host__` and `__device__` through `<complex>` wrapper.
+#include <ymath.h>
+
 #if defined(__cplusplus)
 extern "C" {
 #endif // defined(__cplusplus)