Parser shouldn't raise exceptions, so needs to check when memory
allocation fails. This patch does that for the initial set up of the
parser state.
Also, we now put the parser object on the stack. It's small enough to
go there instead of on the heap.
This partially addresses issue #558.
"object" type in MicroPython currently doesn't implement any methods, and
hopefully, we'll try to stay like that for as long as possible. Even if we
have to add something eventually, look up from there might be handled in
adhoc manner, as last resort (that's not compliant with Python3 MRO, but
we're already non-compliant). Hence: 1) no need to spend type trying to
lookup anything in object; 2) no need to allocate subobject when explicitly
inheriting from object; 3) and having multiple bases inheriting from object
is not a case of incompatible multiple inheritance.
This patch simplifies the glue between native emitter and runtime,
and handles viper code like inline assember: return values are
converted to Python objects.
Fixes issue #531.