Tests: Fix building

Change-Id: I381bb020b75fbc7e43bff6bd2fef5982ed114c14
Reviewed-by: hjk <hjk@theqtcompany.com>

tests/auto/valgrind/memcheck/memcheck.pro

@@ -2,6 +2,8 @@ TEMPLATE = subdirs
 
 parsertests.file = parsertests.pro
 
+# avoid race conditions when compiling shadowbuild and having more than one compile job
+modeldemo.depends = parsertests
 modeldemo.file = modeldemo.pro
 
 testapps.depends = modeldemo parsertests