sim: ppc: change SysV sem & shm tests to compile-time Instead of executing code to see if SysV semaphores & shared memory are available, switch to just a compile-time test. The system used to compile might not match the system used to run the code wrt the current kernel & OS settings, but the library APIs should. So move the failures from compile-time to runtime so the program is more portable, and works correctly even when cross-compiling.