The purpose of this test is to ensure that C++ constructors are executed
  properly during the startup of RIOT. This requires that the port calls
  constructors somewhere during C-library initialization. On newlib ports this is
  done by __libc_init_array(), other ports may need to manually iterate through
  the list of initializer functions (usually .init_array), and call each one in
  order.
  
  There are three tests:
   - Global constructor
   - Static constructor
   - Local constructor
  
  The global constructor test checks to see if the constructor of a global object
  has been run during the boot process. The static constructor test does the
  same, but for static object inside a function. The local constructor test checks
  that a locally created object does have its constructor run.
  The local constructor test will only fail if there is a significant problem with
  the C++ tool chain, since it does not rely on any external C++ support code.