Fixes for degenerate RNG

Assume a degenerate RNG that always returns the same number.
With these fixes, the game starts and is almost playable.
There are still some places that will go into infinite loop, eg.
the mines level generation.

src/role.c

@@ -2028,9 +2028,19 @@ role_init()
 
     /* Fix up the god names */
     if (flags.pantheon == -1) {             /* new game */
+        int trycnt = 0;
         flags.pantheon = flags.initrole;    /* use own gods */
-        while (!roles[flags.pantheon].lgod) /* unless they're missing */
+        /* unless they're missing */
+        while (!roles[flags.pantheon].lgod && ++trycnt < 100)
             flags.pantheon = randrole(FALSE);
+        if (!roles[flags.pantheon].lgod) {
+            int i;
+            for (i = 0; i < SIZE(roles) - 1; i++)
+                if (roles[i].lgod) {
+                    flags.pantheon = i;
+                    break;
+                }
+        }
     }
     if (!g.urole.lgod) {
         g.urole.lgod = roles[flags.pantheon].lgod;