"hex" literals are not handled

[ellab123]

Constant the "hex" prefix has a wrong int value in .bpl file, for example:

bytes1 public data1 = 0x33;
bytes1 public d1 = hex"33";

Assigned values in .bpl file:
data1_Bytes[this] := 51; //correct
d1_Bytes[this] := -1549580528; //wrong

[shuvendu-lahiri]

test is present in comments in BytesTypes.sol by Ella