Sporadically failing CppunitTest_sc_vba_macro_test

[Stephan Bergmann]

At least on (somewhat slow) <https://ci.libreoffice.org/job/lo_ubsan>, 
and also with my local (equally somewhat slow) ASan+UBSan build, I see 
CppunitTest_sc_vba_macro_test occasionally fail with what looks like 
timing issues:

* <https://ci.libreoffice.org/job/lo_ubsan/2773/> and 
<https://ci.libreoffice.org/job/lo_ubsan/2774/> both fail with

> /home/tdf/lode/jenkins/workspace/lo_ubsan/sc/qa/extras/vba-macro-test.cxx:531:testVbaRangeSort::TestBody
> equality assertion failed
> - Expected: 0.5
> - Actual  : 1

* My local ASan+UBSan build occasionally fails with

> sc/qa/extras/vba-macro-test.cxx:499:testTdf149579::TestBody
> equality assertion failed
> - Expected: 1
> - Actual  : 5

In both cases, there is zero indication what exactly goes wrong.  But 
both involve first executing a BASIC script via UnoApiTest::executeMacro 
(which synchronously executes SfxObjectShell::CallXScript, see 
test/source/unoapi_test.cxx) and then checking expected values via 
rDoc.GetValue.

Is it plausible that those macro executions trigger asynchronous 
operations that might only actually update the values (observed via 
rDoc.GetValue) some time after the executeMacro call has already returned?