[SYCL] Fix long long support in vec::convert on Windows

- Keep `long long` and `unsigned long long` in `is_standard_type`.
  Excluding them resulted in duplicate `convertImpl` definitions on
  Windows when converting from `long long` or `unsigned long long`:
  SPIR-V-based and the non-standard type version.
- For to-int SPIR-V-based `convertImpl` overload resolution, compare
  the OpenCL return type with cl_DestType instead of simply DestType
  ((u)char, (u)short, (u)int, (u)long). When converting to `long long`
  or `unsigned long long` on Windows, the non-standard type version
  was used instead of these functions, because `cl_long == long long
  != long` there.

Author: dnmokhov

sycl/include/CL/sycl/types.hpp

@@ -242,9 +242,8 @@ using is_float_to_float =
     std::integral_constant<bool, detail::is_floating_point<T>::value &&
                                      detail::is_floating_point<R>::value>;
 template <typename T>
-using is_standard_type = std::integral_constant<
-    bool, detail::is_sgentype<T>::value && !std::is_same<T, long long>::value &&
-              !std::is_same<T, unsigned long long>::value>;
+using is_standard_type =
+    std::integral_constant<bool, detail::is_sgentype<T>::value>;
 
 template <typename T, typename R, rounding_mode roundingMode, typename OpenCLT,
           typename OpenCLR>
@@ -330,7 +329,7 @@ convertImpl(T Value) {
             typename OpenCLT, typename OpenCLR>                                \
   detail::enable_if_t<is_sint_to_sint<T, R>::value &&                          \
                           !std::is_same<OpenCLT, OpenCLR>::value &&            \
-                          (std::is_same<OpenCLR, DestType>::value ||           \
+                          (std::is_same<OpenCLR, cl_##DestType>::value ||      \
                            (std::is_same<OpenCLR, signed char>::value &&       \
                             std::is_same<DestType, char>::value)),             \
                       R>                                                       \
@@ -352,7 +351,7 @@ __SYCL_GENERATE_CONVERT_IMPL(long)
             typename OpenCLT, typename OpenCLR>                                \
   detail::enable_if_t<is_uint_to_uint<T, R>::value &&                          \
                           !std::is_same<OpenCLT, OpenCLR>::value &&            \
-                          std::is_same<OpenCLR, DestType>::value,              \
+                          std::is_same<OpenCLR, cl_##DestType>::value,         \
                       R>                                                       \
   convertImpl(T Value) {                                                       \
     OpenCLT OpValue = cl::sycl::detail::convertDataToType<T, OpenCLT>(Value);  \
@@ -454,7 +453,7 @@ __SYCL_GENERATE_CONVERT_IMPL_FOR_ROUNDING_MODE(rtn, Rtn)
   template <typename T, typename R, rounding_mode roundingMode,                \
             typename OpenCLT, typename OpenCLR>                                \
   detail::enable_if_t<is_float_to_int<T, R>::value &&                          \
-                          (std::is_same<OpenCLR, DestType>::value ||           \
+                          (std::is_same<OpenCLR, cl_##DestType>::value ||      \
                            std::is_same<OpenCLR, signed char>::value &&        \
                                std::is_same<DestType, char>::value) &&         \
                           RoundingModeCondition<roundingMode>::value,          \