add 32 bit overflow tests
add 32 bit overflow tests

douglas-larocca/solidity,gluk256/solidity,ethers/solidity,debris/solidity,LianaHus/solidity,arkpar/solidity,vaporry/solidity,ruchevits/solidity,shahankhatch/solidity,ruchevits/solidity,ruchevits/solidity,ruchevits/solidity,chriseth/solidity,chriseth/solidity-doc-test