UnitHolder::select_unit logic

cmake-build-debug/CMakeFiles/ftests.dir/CXX.includecache

@@ -195,4 +195,6 @@ iostream
 -
 fstream
 -
+cstdlib
+-
 

cmake-build-debug/conf/test.plan

@@ -1,6 +1,8 @@
 {
     "plan": [
         { "name": "gcc is present", "depends on":  [ null ] },
+        { "name": "gcc can compile", "depends on":  [ "gcc is present" ] },
+        { "name": "gcc can compile2", "depends on":  [ "gcc is present" ] },
         { "name": "gcc can compile", "depends on":  [ "gcc is present" ] }
     ]
 }