Combinational sensitivity detection is excessively pessimistic

[mkorbel1]

Describe the bug

The current implementation that searches for expanded sensitivity lists in Combinational will not look "inside" other Modules along the path from its outputs to inputs. If a Sequential is inside of another Module along the path, it will skip over it assuming that any input may have a combinational path to any output. This is excessively pessimistic, and can lead to detection of non-existent combinational loops in Logic reentrance checking.

To Reproduce

Connections like shown below will reproduce this issue:

  ______________________
  | Module             |
--|<-- [Sequential] <--|--
| |____________________| |
|                        |
---->[Combinational]----->

If the combinational in the diagram is also responsible for driving some other input to the module, it can cause a false combinational loop detection.

Expected behavior

No invalid detection of combinational loops.

Actual behavior

X generation due to reentrance detection in Logic.put

Additional: Dart SDK info

No response

Additional: pubspec.yaml

No response

Additional: Context

No response