From https://github.com/pfalcon/berkeley-db-1.xx, which so far contains
pristine 1.85, but will get patches and compile warning fixes going
Berkeley DB 1.xx is BSD-licensed, and will form the basis of "btree"
simple database module.
This allows to build libffi from source together with micropython, and is
useful for cross-compilation. Support for this was already merged
previously, to use:
(To both commands appropriate cross-compilition flags can be added).