Add static create method for complex so it's compatible with hlsl codepath

Author: Fletterio

include/nbl/builtin/hlsl/complex.hlsl

@@ -21,7 +21,16 @@ namespace hlsl
 {
 
 template<typename Scalar>
-using complex_t = std::complex<Scalar>;
+struct complex_t : public std::complex<Scalar>
+{
+    using base_t = std::complex<Scalar>;
+    complex_t(const Scalar real, const Scalar imag) : base_t(real, imag) {}
+    static complex_t create(const Scalar real, const Scalar imag)
+    {
+        complex_t retVal(real, imag);
+        return retVal;
+    }
+};
 
 // Fast mul by i
 template<typename Scalar>
@@ -463,4 +472,4 @@ NBL_REGISTER_OBJ_TYPE(complex_t<float64_t4>,::nbl::hlsl::alignment_of_v<float64_
 // -------------------------------------- END HLSL VERSION ---------------------------------------
 #endif
 
-#endif
+#endif