Makes it compatible with the __builtin_mul_overflow() syntax, used in
follow-up commit.
Includes optimisation in runtime.c to minimise the code size impact from
additional param.
Signed-off-by: Damien George <damien@micropython.org>
Signed-off-by: Angus Gratton <angus@redyak.com.au>
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/.