Fix LTO segfault in libtest_sw_uwriter test.

The problem was seen here:
https://bugzilla.suse.com/show_bug.cgi?id=1127857.

One needs to call SwGlobals::ensure in order to initialize
SfxApplication via SfxApplication::SetModule(SfxToolsModule::Writer.

Change-Id: I3add24b56dc44a93ad81c1b52539da821f6244fc
Reviewed-on: https://gerrit.libreoffice.org/68839
Tested-by: Jenkins
Reviewed-by: Tomáš Chvátal <tchvatal@suse.cz>

sw/qa/core/test_ToxTextGenerator.cxx

@@ -22,10 +22,17 @@
 #include <cppunit/extensions/HelperMacros.h>
 #include <cppunit/plugin/TestPlugIn.h>
 
+#include <swdll.hxx>
+
 using namespace sw;
 
 class ToxTextGeneratorTest : public CppUnit::TestFixture {
 public:
+    virtual void setUp() override
+    {
+        SwGlobals::ensure();
+    }
+
     void EmptyStringIsReturnedForPageNumberPlaceholderOfZeroItems();
     void OneAtSignIsReturnedForPageNumberPlaceholderOfOneItem();
     void TwoAtSignsAreReturnedForPageNumberPlaceholderOfOneItem();