refs #5801 fix breverse, get flt1 reproducing and passing again

git-svn-id: file:///svn/toku/tokudb@51751 c7de825b-a66e-492c-adef-691d508d4ae1

src/tests/recover-test_crash_in_flusher_thread.h

@@ -87,6 +87,7 @@ run_recover_flt_test(int argc, char *const argv[]) {
     }
     // we want to induce a checkpoint
     args.env_args.checkpointing_period = 0;
+    args.env_args.cachetable_size = 20 * 1024 * 1024;
     parse_stress_test_args(argc, argv, &args);
     if (args.do_test_and_crash) {
         stress_test_main(&args);

src/tests/threaded_stress_test_helpers.h

@@ -666,7 +666,7 @@ static int64_t breverse(int64_t v)
     }
     k <<= s; // shift when v's highest bits are zero
     int64_t r = k;
-    return r < 0 ? -r : r;
+    return r & ~(1ULL << 63);
 }
 
 static void