[NFC][libspirv] Simplify macros in __spirv_ocl_smoothstep (#20400)

Author: wenju-he

libclc/libspirv/lib/generic/common/smoothstep.cl

@@ -9,32 +9,7 @@
 #include <clc/common/clc_smoothstep.h>
 #include <libspirv/spirv.h>
 
-#define SMOOTHSTEP_SINGLE_DEF(X_TYPE)                                          \
-  _CLC_OVERLOAD _CLC_DEF X_TYPE __spirv_ocl_smoothstep(                        \
-      X_TYPE edge0, X_TYPE edge1, X_TYPE x) {                                  \
-    return __clc_smoothstep(edge0, edge1, x);                                  \
-  }
-
-#define SMOOTHSTEP_DEF(type)                                                   \
-  SMOOTHSTEP_SINGLE_DEF(type)                                                  \
-  SMOOTHSTEP_SINGLE_DEF(type##2)                                               \
-  SMOOTHSTEP_SINGLE_DEF(type##3)                                               \
-  SMOOTHSTEP_SINGLE_DEF(type##4)                                               \
-  SMOOTHSTEP_SINGLE_DEF(type##8)                                               \
-  SMOOTHSTEP_SINGLE_DEF(type##16)
-
-SMOOTHSTEP_DEF(float)
-
-#ifdef cl_khr_fp64
-#pragma OPENCL EXTENSION cl_khr_fp64 : enable
-
-SMOOTHSTEP_DEF(double);
-
-#endif
-
-#ifdef cl_khr_fp16
-#pragma OPENCL EXTENSION cl_khr_fp16 : enable
-
-SMOOTHSTEP_DEF(half);
-
-#endif
+#define __CLC_FUNCTION __spirv_ocl_smoothstep
+#define __CLC_IMPL_FUNCTION(x) __clc_smoothstep
+#define __CLC_BODY <clc/shared/ternary_def.inc>
+#include <clc/math/gentype.inc>