Cleanup of TValue setters. No functional changes.

src/lj_api.c

@@ -1101,7 +1101,7 @@ LUA_API int lua_yield(lua_State *L, int nresults)
       top->u64 = cframe_multres(cf);
       setcont(top+1, lj_cont_hook);
       setframe_pc(top+1, cframe_pc(cf)-1);
-      setframe_gc(top+2, obj2gco(L));
+      setframe_gc(top+2, obj2gco(L), LJ_TTHREAD);
       setframe_ftsz(top+2, ((char *)(top+3)-(char *)L->base)+FRAME_CONT);
       L->top = L->base = top+3;
 #if LJ_TARGET_X64