tests: Add missing Jam rule for mmap_cut_tests.

src/tests/system/kernel/Jamfile

@@ -55,6 +55,7 @@ SimpleTest port_wakeup_test_8 : port_wakeup_test_8.cpp ;
 SimpleTest port_wakeup_test_9 : port_wakeup_test_9.cpp ;
 
 SimpleTest mmap_resize_test : mmap_resize_test.cpp ;
+SimpleTest mmap_cut_tests : mmap_cut_tests.cpp ;
 
 SimpleTest null_poll_test : null_poll_test.cpp ;