Type inference of abs with user-defined argument type fails

[JukkaL]

The type inference of the final line in this example fails:

class A(SupportsAbs[float]):
    def __abs__(self) -> float: return 5.5

print(abs(A()))        # Error

The abs type argument should be inferred automatically.

[JukkaL]

See also pythoneval test case testGenericFunctionTypeInferenceProblem.

[JukkaL]

There seems to be at least two related bugs. The first one is #410.

[JukkaL]

However, the original example now works correctly -- originally there must have been three bugs around this issue!

[JukkaL]

testGenericFunctionTypeInferenceProblem was actually broken, and there only seems to be the related bug #410.