The GC now works correctly using asyncify and the functions
emscripten_scan_stack() and emscripten_scan_registers(). Stack/call depth
is monitored via the use of the pystack option.
Fixes issue #6738.
Signed-off-by: Damien George <damien@micropython.org>
In this port JavaScript is the underlying "machine" and MicroPython is
transmuted into JavaScript by Emscripten. MicroPython can then run under
Node.js or in the browser.