Test code to verify encode/decode of function signatures into a 16bit value. This is for compatibility with .NET runtime.
Encodes whether parameters are 4 or 8 bytes as 2 bit values (0b01 and 0b10 respectively), the first parameter code is always shifted left 12 bits, with up to 6 parameters. The last 2 bits are used to indicate the return type.
Will be adding enum generation code - probably python