Fix linkage on msvc2015

This does not link without this explicit compare
function after the QLatin1Strings have been removed.

Change-Id: I09cd323f850954eedefed6ee58597cb0ef3ab026
Reviewed-by: hjk <hjk@qt.io>

src/plugins/valgrind/valgrindmemcheckparsertest.cpp

@@ -56,6 +56,12 @@ inline bool qCompare(int const &t1, MemcheckErrorKind const &t2,
     return qCompare(t1, int(t2), actual, expected, file, line);
 }
 
+inline bool qCompare(const QString &t1, char const *t2,
+                     char const *actual, char const *expected, char const *file, int line)
+{
+    return qCompare(t1, QString::fromLatin1(t2), actual, expected, file, line);
+}
+
 } // namespace QTest
 QT_END_NAMESPACE