Draft approach towards resolving https://github.com/micropython/micropython/issues/560#issuecomment-42213955
unix: Create __bss_start and _end symbols for Mach-O targets.

It's a hack, but can't find a cleaner way to do it.
tests: create result file for test/basics/memoryerror.py .

On Mac OS "python3 test/basics/memoryerror.py" never runs out of memory, the process is frozen by the os before.
unix: Add asm statements needed to read registers with clang. Code generated by gcc 4.9.0 is unchanged (same statements, different order).

Both are inefficient, saving unmodified registers on the stack.
Fix some unused variables, and silence a clang warning about initialization override in vmentrytable.h
Merge pull request #615 from swegener/for-upstream

py: Fix mp_obj_t -> mp_const_obj_t for mp_obj_int_get_checked()
stmhal: Activate bootloader with pyb.bootloader()

Signed-off-by: Sven Wegener <sven.wegener@stealer.net>
stmhal: Remap system flash and adjust addresses

Signed-off-by: Sven Wegener <sven.wegener@stealer.net>
Merge pull request #618 from swegener/jump-to-bootloader

Jump to bootloader
stmhal: Make pyb.bootloader take no arguments.
stmhal: Fix write_timed function for DAC(2).

Addresses issue #617.
stmhal: Fix DAC documentation: need to convert float to int for buf.
objtype: Separate __new__ and __init__ methods.

Now schedule is: for native types, we call ->make_new() C-level method, which
should perform actions of __new__ and __init__ (note that this is not
compliant, but is efficient), but for user types, __new__ and __init__ are
called as expected.

Also, make sure we convert scalar attribute value to a bound-pair tight in
mp_obj_class_lookup() method, which avoids converting it again and again in
its callers.
tests: Update subclass-native2.py for __new__/__init__ refactor.

Now case of subclassing tuple works, and list is broken, see comments.
objexcept: Implement explicit __init__ method, useful for subclasses.
py: Implement proper separation between io.FileIO and io.TextIOWrapper.

io.FileIO is binary I/O, ans actually optional. Default file type is
io.TextIOWrapper, which provides str results. CPython3 explicitly describes
io.TextIOWrapper as buffered I/O, but we don't have buffering support yet
anyway.
qemu-arm: Disable "io" module.
windows: Fix compilation with mingw-w64 so it uses correct printf implementations

Without this flag, mingw-w64 uses the MS implementations of snpintf and the likes.
This is not really a problem since they work with the the fixes provided for msvc,
but due to the way mingw-w64's stdio.h is structured we cannot get it to use the fixes.
modstruct: struct_calcsize: Fix case of uninitialized var.
Merge pull request #621 from stinos/migw-w64-fix

windows: Fix compilation with mingw-w64 so it uses correct printf implem...