Use of -a switch breaks imports

Run the two transcrypt commands from the report with the provided test.py example and compare their generated imports. Trace the -a switch handling and import generation, including subsequent * imports and from package import my_module. Done means -a preserves the required runtime imports while retaining the working explicit module import behavior.

I was looking into a recent issue (#616) and it seems there's a bug when using the -a switch.

test.py
print("hello")

transcrypt -n output.js
// Transcrypt'ed from Python, 2019-04-26 09:45:28
import {AssertionError, AttributeError, BaseException, DeprecationWarning, Exception, IndexError, IterableError, KeyError, NotImplementedError, RuntimeWarning, StopIteration, UserWarning, ValueError, Warning, __JsIterator__, __PyIterator__, __Terminal__, __add__, __and__, __call__, __class__, __envir__, __eq__, __floordiv__, __ge__, __get__, __getcm__, __getitem__, __getslice__, __getsm__, __gt__, __i__, __iadd__, __iand__, __idiv__, __ijsmod__, __ilshift__, __imatmul__, __imod__, __imul__, __in__, __init__, __ior__, __ipow__, __irshift__, __isub__, __ixor__, __jsUsePyNext__, __jsmod__, __k__, __kwargtrans__, __le__, __lshift__, __lt__, __matmul__, __mergefields__, __mergekwargtrans__, __mod__, __mul__, __ne__, __neg__, __nest__, __or__, __pow__, __pragma__, __proxy__, __pyUseJsNext__, __rshift__, __setitem__, __setproperty__, __setslice__, __sort__, __specialattrib__, __sub__, __super__, __t__, __terminal__, __truediv__, __withblock__, __xor__, abs, all, any, assert, bool, bytearray, bytes, callable, chr, copy, deepcopy, delattr, dict, dir, divmod, enumerate, filter, float, getattr, hasattr, input, int, isinstance, issubclass, len, list, map, max, min, object, ord, pow, print, property, py_TypeError, py_iter, py_metatype, py_next, py_reversed, py_typeof, range, repr, round, set, setattr, sorted, str, sum, tuple, zip} from './org.transcrypt.__runtime__.js';
var __name__ = '__main__';
print ('hello');

//# sourceMappingURL=sketch.map

transcrypt -n -a output.js
/* 000001 */ // Transcrypt'ed from Python, 2019-04-26 09:44:46
/* 000001 */ import {} from './org.transcrypt.__runtime__.js';
/* 000001 */ var __name__ = '__main__';
/* 000001 */ print ('hello');
/* 000001 */ 
//# sourceMappingURL=sketch.map

Nothing will be imported from transcrypt. In other tests, I determined that it will also ignore any subsequent * imports but will render from package import my_module just fine.

Using transcrypt 3.7.12 on Windows 10