Fix macro definition for clangcl

Author: Beanavil

CL/cl_platform.h

@@ -74,10 +74,10 @@ extern "C" {
 #define CL_API_SUFFIX__EXPERIMENTAL CL_API_SUFFIX_COMMON
 
 
-#ifdef __GNUC__
+#ifdef(__GNUC__)
   #define CL_API_SUFFIX_DEPRECATED __attribute__((deprecated))
   #define CL_API_PREFIX_DEPRECATED
-#elif defined(_WIN32)
+#elif defined(_MSC_VER) && !defined(__clang__)
   #define CL_API_SUFFIX_DEPRECATED
   #define CL_API_PREFIX_DEPRECATED __declspec(deprecated)
 #else