bfloat support for SPV_INTEL_sigmoid

Current SPV_INTEL_sigmoid spec does not allow bfloat type,
but it will be added as an update to SPV_INTEL_bfloat16_arithmetic spec.
This commit prepares the implementation for this addition.

Author: PawelJurek

IGC/BiFModule/Implementation/Math/sigm.cl

@@ -43,14 +43,23 @@ GENERATE_SPIRV_OCL_VECTOR_FUNCTIONS_1ARG_LOOP( sigm, half, half, f16 )
 // SPV_INTEL_sigmoid extension
 float __attribute__((overloadable)) __spirv_FSigmoidINTEL( float x )
 {
-    return __spirv_ocl_sigm( x );
+    return __spirv_ocl_sigm(x);
 }
 SPIRV_GENERATE_VECTOR_FUNCTIONS_1ARG( FSigmoidINTEL, float, float, f32 )
 
 #if defined(cl_khr_fp16)
 half __attribute__((overloadable)) __spirv_FSigmoidINTEL( half x )
 {
-    return __spirv_ocl_sigm( x );
+    return __spirv_ocl_sigm(x);
 }
 SPIRV_GENERATE_VECTOR_FUNCTIONS_1ARG( FSigmoidINTEL, half, half, f16 )
 #endif // defined(cl_khr_fp16)
+
+// bfloat16 - short is used to represent bfloat16, it is changed later
+// in BfloatBuiltinsResolution to bfloat type.
+
+short __attribute__((overloadable)) __spirv_FSigmoidINTEL( short x )
+{
+    return __spirv_ocl_sigm(__builtin_IB_bftof_1(x));
+}
+SPIRV_GENERATE_VECTOR_FUNCTIONS_1ARG( FSigmoidINTEL, short, short, bf16 )