Merge branch 'master' into v2.1

diff --cc src/lj_api.c
Simple merge

diff --cc src/lj_gc.c
Simple merge

diff --cc src/lj_record.c
index b7af5896970f0682418adba5854f03de1dc7bba6,f2a06f41cdf386ceeea8f44f3c474e3193063532..a9092d92d1401c3fb4b39d488d49f0c38f8c39eb
--- 1/src/lj_record.c
--- 2/src/lj_record.c
+++ b/src/lj_record.c
@@@ -948,10 -728,10 +948,10 @@@ void lj_record_ret(jit_State *J, BCReg 
      if ((pt->flags & PROTO_NOJIT))
        lj_trace_err(J, LJ_TRERR_CJITOFF);
      if (J->framedepth == 0 && J->pt && frame == J->L->base - 1) {
-       if (check_downrec_unroll(J, pt)) {
+       if (!J->cur.root && check_downrec_unroll(J, pt)) {
        J->maxslot = (BCReg)(rbase + gotresults);
        lj_snap_purge(J);
 -      rec_stop(J, LJ_TRLINK_DOWNREC, J->cur.traceno);  /* Down-recursion. */
 +      lj_record_stop(J, LJ_TRLINK_DOWNREC, J->cur.traceno);  /* Down-rec. */
        return;
        }
        lj_snap_add(J);