Fix flappiness of test_refc_binaries

In some circumstances, `erlang:memory(binary)` returns the space used by a refc binary from the previous test.
Ensure everything is cleaned up by calling gc before sending result.

Monitor wouldn’t help because monitor message is sent before mso is swept.

Also remove useless gc before the test as the process was freshly spawned.

Signed-off-by: Paul Guyot <[email protected]>

tests/erlang_tests/test_refc_binaries.erl

@@ -236,7 +236,6 @@ run_test(Fun) ->
     end.
 
 execute(Pid, Fun) ->
-    erlang:garbage_collect(),
     Result =
         try
             Fun(),
@@ -245,6 +244,7 @@ execute(Pid, Fun) ->
             _:Error ->
                 {error, Error}
         end,
+    erlang:garbage_collect(),
     Pid ! Result.
 
 id(X) -> X.