make: unifdef for other OSes (undefined)

@@ -440,15 +440,11 @@
 
 #include <unistd.h>     /* sysconf(_SC_NPROCESSORS_ONLN) */
 #include <sys/ipc.h>            /* ftok() */
 #include <sys/shm.h>            /* shmget(), shmat(), shmdt(), shmctl() */
 #include <semaphore.h>          /* sem_init(), sem_trywait(), sem_post(), sem_destroy() */
-#if defined(linux)
-#define LOADAVG_1MIN    0
-#else
 #include <sys/loadavg.h>        /* getloadavg() */
-#endif /* linux */
 
 /*
  *      adjust_pmake_max_jobs (int pmake_max_jobs)
  *
  *      Parameters:

@@ -2172,15 +2168,10 @@
                                         DO_CHECK(fprintf(scrfp, NOCATGETS("/usr/bin/printf '%%s\\n' %s\n"), mbst));
                                 }
                                 if (!do_not_exec_rule ||
                                     !working_on_targets ||
                                     always_exec) {
-#if defined(linux)
-                                        if (0 != strcmp(shell->string_mb, (char*)NOCATGETS("/bin/sh"))) {
-                                                DO_CHECK(fprintf(scrfp, NOCATGETS("%s -c %s\n"), shell->string_mb, cmd));
-                                        } else
-#endif
                                         DO_CHECK(fprintf(scrfp, NOCATGETS("%s -ce %s\n"), shell->string_mb, cmd));
                                         DO_CHECK(fputs(NOCATGETS("__DMAKECMDEXITSTAT=$?\nif [ ${__DMAKECMDEXITSTAT} -ne 0 ]; then\n"), scrfp));
                                         if (ignore) {
                                                 DO_CHECK(fprintf(scrfp, NOCATGETS("\techo %s ${__DMAKECMDEXITSTAT} %s\n"),
                                                         catgets(catd, 1, 343, "\"*** Error code"),