Let CONFIG+=no_default_target also disable `check' by default

If the compilation of a subdir was explicitly disabled by default, then
the testing of that subdir should also be disabled by default.

Change-Id: I928e232393e89a7c27813b7a48864d4e0fb687f8
Reviewed-on: http://codereview.qt.nokia.com/2835
Reviewed-by: Qt Sanity Bot <qt_sanity_bot@ovi.com>
Reviewed-by: Kalle Lehtonen <kalle.ju.lehtonen@nokia.com>

mkspecs/features/default_post.prf

@@ -99,10 +99,16 @@ QMAKE_LIBDIR += $$QMAKE_LIBDIR_POST
 # Let every project have a standard GNU `check' target
 !contains(QMAKE_EXTRA_TARGETS, check) {
     # `make check' should iterate through all subdirs
+    # (except those with no_default_target)
     contains(TEMPLATE, subdirs) {
         check.CONFIG = recursive
-        check.recurse = $$SUBDIRS
         check.recurse_target = check
+
+        for(subdir, SUBDIRS) {
+            subdir_config=$$eval($${subdir}.CONFIG)
+            !contains(subdir_config, no_default_target):check.recurse += $$subdir
+            unset(subdir_config)
+        }
     }
     # `make check' should imply building the project
     else {