Rationale: setting up the stack (state for locals and exceptions) is
really part of the "code", it's the prelude of the function. For
example, native code adjusts the stack pointer on entry to the function.
Native code doesn't need to know n_state for any other reason. So
putting the state size in the bytecode prelude is sensible.
It reduced ROM usage on STM by about 30 bytes :) And makes it easier to
pass information about the bytecode between functions.
Originally, .methods was used for methods in a ROM class, and
locals_dict for methods in a user-created class. That distinction is
unnecessary, and we can use locals_dict for ROM classes now that we have
ROMable maps.
This removes an entry in the bloated mp_obj_type_t struct, saving a word
for each ROM object and each RAM object. ROM objects that have a
methods table (now a locals_dict) need an extra word in total (removed
the methods pointer (1 word), no longer need the sentinel (2 words), but
now need an mp_obj_dict_t wrapper (4 words)). But RAM objects save a
word because they never used the methods entry.
Overall the ROM usage is down by a few hundred bytes, and RAM usage is
down 1 word per user-defined type/class.
There is less code (no need to check 2 tables), and now consistent with
the way ROM modules have their tables initialised.
Efficiency is very close to equivaluent.
This gets "value" of exceptions in the sense as it's defined for
StopIteration.value (i.e. args[0] or None).
TODO: This really should be inline function.
Return with value gets converted to StopIteration(value). Implementation
keeps optimizing against creating of possibly unneeded exception objects,
so there're considerable refactoring to implement these features.
For this, needed to implement DELETE_NAME bytecode (because var bound
in except clause is automatically deleted at its end).
http://docs.python.org/3/reference/compound_stmts.html#except :
"When an exception has been assigned using as target, it is cleared at
the end of the except clause."
Made solely to unbreak int-long.py test which in turn uncovered thinko
with implementation of inplace ops. On mpz level, bitwise ops implemented
only for same-sign numbers, and are not efficient (unconditional calling of
mpn_cmp() is apparently superfluous).
