Add missing definitions for class static members

The static members __HIP_Coordinates::x, ::y and ::z must be defined
outside the class. Otherwise, linker throws `undefined reference error`
when these definitions are needed in the HIP application.

Change-Id: Iabc09744b478c22e4b13cf9824877ec9cfdd4f7a

include/hip/hcc_detail/hip_runtime.h

@@ -487,6 +487,22 @@ struct __HIP_Coordinates {
 #endif
 
 };
+template <typename F>
+#if !defined(_MSC_VER)
+__attribute__((weak))
+#endif
+constexpr typename __HIP_Coordinates<F>::X __HIP_Coordinates<F>::x;
+template <typename F>
+#if !defined(_MSC_VER)
+__attribute__((weak))
+#endif
+constexpr typename __HIP_Coordinates<F>::Y __HIP_Coordinates<F>::y;
+template <typename F>
+#if !defined(_MSC_VER)
+__attribute__((weak))
+#endif
+constexpr typename __HIP_Coordinates<F>::Z __HIP_Coordinates<F>::z;
+
 extern "C" __device__ __attribute__((const)) size_t __ockl_get_global_size(uint);
 inline
 __device__