Create a Target instance for the given triple (a string).

def from_triple(cls, triple):
        """
        Create a Target instance for the given triple (a string).
        """
        with ffi.OutputString() as outerr:
            target = ffi.lib.LLVMPY_GetTargetFromTriple(triple.encode('utf8'),
                                                        outerr)
            if not target:
                raise RuntimeError(str(outerr))
            target = cls(target)
            target._triple = triple
            return target