Merge pull request #601 from crytic/dev-support-return-func-pointer

IR: Add support for function pointer in RETURN operator

slither/slithir/operations/return_operation.py

@@ -1,3 +1,4 @@
+from slither.core.declarations import Function
 from slither.slithir.operations.operation import Operation
 
 from slither.slithir.variables.tuple import TupleVariable
@@ -15,7 +16,7 @@ class Return(Operation):
         # ex: return call()
         # where call() dont return
         if not isinstance(values, list):
-            assert is_valid_rvalue(values) or isinstance(values, TupleVariable) or values is None
+            assert is_valid_rvalue(values) or isinstance(values, (TupleVariable, Function)) or values is None
             if values is None:
                 values = []
             else:
@@ -34,7 +35,7 @@ class Return(Operation):
         if isinstance(value, list):
             assert all(self._valid_value(v) for v in value)
         else:
-            assert is_valid_rvalue(value) or isinstance(value, TupleVariable)
+            assert is_valid_rvalue(value) or isinstance(value, (TupleVariable, Function))
         return True
 
     @property