[WIP] Implement subroutine opcodes

Author: Peppece

eth/vm/rstack.py

@@ -61,6 +61,6 @@ def pop1_int(self, value) -> int:
                 return big_endian_to_int(popped)  # type: ignore
             else:
                 raise ValidationError(
-                   "Stack must always be bytes or int, "
-                   f"got {item_type!r} type, val {value!r}"
+                    "Stack must always be bytes or int, "
+                    f"got {item_type!r} type, val {value!r}"
                 )

tests/core/opcodes/test_opcodes.py

@@ -1159,7 +1159,7 @@ def test_jumpsub(vm_class, code, expect_gas_used):
     assert comp.get_gas_used() == expect_gas_used
 
 
-@pytest.mark.xfail(reason="invalid subroutines") # noqa: F811
+@pytest.mark.xfail(reason="invalid subroutines")  # noqa: F811
 @pytest.mark.parametrize(
     'vm_class, code',
     (