This is to keep the top-level directory clean, to make it clear what is
core and what is a port, and to allow the repository to grow with new ports
in a sustainable way.
None of the other ports do, since introduction of mp_state_ctx_t. In
the case of current esp8266 port, heap is inside BSS, so scanning it
picked up a lot of dead pointers.
As user_init() is not a true main functions, the stack pointer captured within
is not pointing at the base of the stack. This caused gc_collect being called
with sp being higher than stack_end, causing integer overflow and crashing as
gc tried to scan almost the entire address space.
Blanket wide to all .c and .h files. Some files originating from ST are
difficult to deal with (license wise) so it was left out of those.
Also merged modpyb.h, modos.h, modstm.h and modtime.h in stmhal/.