rtems test harness setup to create temp files

Apparently the default location for tmp files
doesn't exist in the default IMFS tree.

src/ioc/db/test/rtemsTestHarness.c

@@ -5,10 +5,32 @@
 * in file LICENSE that is included with this distribution.
 \*************************************************************************/
 
+
+#ifdef __rtems__
+
+#include <stdio.h>
+#include <envDefs.h>
+#include <sys/stat.h>
+#include <sys/types.h>
+
+#endif /* __rtems__ */
+
 extern void epicsRunDbTests(void);
 
 int main(int argc, char **argv)
 {
+#ifdef __rtems__
+    struct stat s;
+    printf("Try to create /tmp\n");
+    umask(0);
+    if(mkdir("/tmp", 0777)!=0)
+        perror("Can't create /tmp");
+    if(stat("/tmp", &s)==0) {
+        printf("Stat /tmp: %o %u,%u\n", s.st_mode, s.st_uid, s.st_gid);
+    }
+    epicsEnvSet("TMPDIR","/tmp");
+#endif
+
     epicsRunDbTests();  /* calls epicsExit(0) */
     return 0;
 }