Attempt to address issue #386. unique_code_id's have been removed and
replaced with a pointer to the "raw code" information. This pointer is
stored in the actual byte code (aligned, so the GC can trace it), so
that raw code (ie byte code, native code and inline assembler) is kept
only for as long as it is needed. In memory it's now like a tree: the
outer module's byte code points directly to its children's raw code. So
when the outer code gets freed, if there are no remaining functions that
need the raw code, then the children's code gets freed as well.
This is pretty much like CPython does it, except that CPython stores
indexes in the byte code rather than machine pointers. These indices
index the per-function constant table in order to find the relevant
code.
Very little has changed. In Python 3.4 they removed the opcode
STORE_LOCALS, but in Micro Python we only ever used this for CPython
compatibility, so it was a trivial thing to remove. It also allowed to
clean up some dead code (eg the 0xdeadbeef in class construction), and
now class builders use 1 less stack word.
Python 3.4.0 introduced the LOAD_CLASSDEREF opcode, which I have not
yet understood. Still, all tests (apart from bytecode test) still pass.
Bytecode tests needs some more attention, but they are not that
important anymore.
Mostly just a global search and replace. Except rt_is_true which
becomes mp_obj_is_true.
Still would like to tidy up some of the names, but this will do for now.
LOAD_METHOD bug was: emitbc did not correctly calculate the amount of
stack usage for a LOAD_METHOD operation.
small int bug was: int was being used to pass small ints, when it should
have been machine_int_t.
With MICROPY_EMIT_X64 and MICROPY_EMIT_THUMB disabled, the respective
emitters and assemblers will not be included in the code. This can
significantly reduce binary size for unix version.
A big change. Micro Python objects are allocated as individual structs
with the first element being a pointer to the type information (which
is itself an object). This scheme follows CPython. Much more flexible,
not necessarily slower, uses same heap memory, and can allocate objects
statically.
Also change name prefix, from py_ to mp_ (mp for Micro Python).
