silence some warnings while building inchi code with modern clang
silence some warnings while building inchi code with modern clang

rdkit/rdkit,rdkit/rdkit,bp-kelley/rdkit,greglandrum/rdkit,ptosco/rdkit,ptosco/rdkit,ptosco/rdkit,bp-kelley/rdkit,greglandrum/rdkit,greglandrum/rdkit,rdkit/rdkit,ptosco/rdkit,rdkit/rdkit,ptosco/rdkit,rdkit/rdkit,ptosco/rdkit,greglandrum/rdkit,rdkit/rdkit,greglandrum/rdkit,bp-kelley/rdkit,bp-kelley/rdkit,greglandrum/rdkit,rdkit/rdkit,bp-kelley/rdkit,greglandrum/rdkit,bp-kelley/rdkit,ptosco/rdkit,rdkit/rdkit,bp-kelley/rdkit,bp-kelley/rdkit,greglandrum/rdkit,ptosco/rdkit