[SYCL] Add sycl wrappers for fp conversions. (#9431)

This PR adds C++ wrappers in intel math header for type conversion
functions provided in SYCL libdevice.
The function names align with CUDA correspondence but we don't use "__"
prefix in function name.
For example, CUDA __double2float_ru maps to
sycl::ext::intel::math::double2float_ru.

---------

Signed-off-by: jinge90 <[email protected]>

Author: jinge90

sycl/include/sycl/ext/intel/math.hpp

@@ -1,4 +1,4 @@
-//==------------- math.hpp - Intel specific math API -----------------------==//
+//==-------------- math.hpp - Intel specific math API ----------------------==//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
@@ -9,11 +9,6 @@
 //===----------------------------------------------------------------------===//
 
 #pragma once
-#include <sycl/builtins.hpp>
-#include <sycl/ext/intel/math/imf_half_trivial.hpp>
-#include <sycl/ext/intel/math/imf_simd.hpp>
-#include <sycl/half_type.hpp>
-#include <type_traits>
 
 // _iml_half_internal is internal representation for fp16 type used in intel
 // math device library. The definition here should align with definition in
@@ -24,6 +19,14 @@ using _iml_half_internal = _Float16;
 using _iml_half_internal = uint16_t;
 #endif
 
+#include <sycl/builtins.hpp>
+#include <sycl/ext/intel/math/imf_fp_conversions.hpp>
+#include <sycl/ext/intel/math/imf_half_trivial.hpp>
+#include <sycl/ext/intel/math/imf_simd.hpp>
+#include <sycl/ext/oneapi/bfloat16.hpp>
+#include <sycl/half_type.hpp>
+#include <type_traits>
+
 extern "C" {
 float __imf_saturatef(float);
 float __imf_copysignf(float, float);