Refactor prng to not use 64-bit atomics on 32-bit platforms.

This resolves #495.

src/arena.c

@@ -422,8 +422,8 @@ arena_decay_deadline_init(arena_t *arena)
 	if (arena->decay.time > 0) {
 		nstime_t jitter;
 
-		nstime_init(&jitter, prng_range(&arena->decay.jitter_state,
-		    nstime_ns(&arena->decay.interval), false));
+		nstime_init(&jitter, prng_range_u64(&arena->decay.jitter_state,
+		    nstime_ns(&arena->decay.interval)));
 		nstime_add(&arena->decay.deadline, &jitter);
 	}
 }
@@ -1680,7 +1680,7 @@ arena_new(tsdn_t *tsdn, unsigned ind)
 		 * deterministic seed.
 		 */
 		arena->offset_state = config_debug ? ind :
-		    (uint64_t)(uintptr_t)arena;
+		    (size_t)(uintptr_t)arena;
 	}
 
 	arena->dss_prec = extent_dss_prec_get();

src/ckh.c

@@ -99,8 +99,8 @@ ckh_try_bucket_insert(ckh_t *ckh, size_t bucket, const void *key,
 	 * Cycle through the cells in the bucket, starting at a random position.
 	 * The randomness avoids worst-case search overhead as buckets fill up.
 	 */
-	offset = (unsigned)prng_lg_range(&ckh->prng_state, LG_CKH_BUCKET_CELLS,
-	    false);
+	offset = (unsigned)prng_lg_range_u64(&ckh->prng_state,
+	    LG_CKH_BUCKET_CELLS);
 	for (i = 0; i < (ZU(1) << LG_CKH_BUCKET_CELLS); i++) {
 		cell = &ckh->tab[(bucket << LG_CKH_BUCKET_CELLS) +
 		    ((i + offset) & ((ZU(1) << LG_CKH_BUCKET_CELLS) - 1))];
@@ -142,8 +142,8 @@ ckh_evict_reloc_insert(ckh_t *ckh, size_t argbucket, void const **argkey,
 		 * were an item for which both hashes indicated the same
 		 * bucket.
 		 */
-		i = (unsigned)prng_lg_range(&ckh->prng_state,
-		    LG_CKH_BUCKET_CELLS, false);
+		i = (unsigned)prng_lg_range_u64(&ckh->prng_state,
+		    LG_CKH_BUCKET_CELLS);
 		cell = &ckh->tab[(bucket << LG_CKH_BUCKET_CELLS) + i];
 		assert(cell->key != NULL);
 

src/prof.c

@@ -878,7 +878,7 @@ prof_sample_threshold_update(prof_tdata_t *tdata)
 	 *   pp 500
 	 *   (http://luc.devroye.org/rnbookindex.html)
 	 */
-	r = prng_lg_range(&tdata->prng_state, 53, false);
+	r = prng_lg_range_u64(&tdata->prng_state, 53);
 	u = (double)r * (1.0/9007199254740992.0L);
 	tdata->bytes_until_sample = (uint64_t)(log(u) /
 	    log(1.0 - (1.0 / (double)((uint64_t)1U << lg_prof_sample))))