These allow to fine-tune the compiler to select whether it optimises
tuple assignments of the form a, b = c, d and a, b, c = d, e, f.
Sensible defaults are provided.
Unlike bare-arm, which is mostly intended to show raw interpreter size,
without library and support code dependencies. This port is intended to
be a better base to start new ports, and also will include emulation
build to allow debug some aspects of embedded targets on POSIX systems.
This initial commit is verbatim copy of bare-arm code.
