src/lfunc.js: Fix luaF_findupval, it needs to insert the upvalue into correct place in linked list, not the start
src/lfunc.js: Fix luaF_findupval, it needs to insert the upvalue into correct place in linked list, not the start

fengari-lua/fengari,giann/fengari,dlbd/fengari,daurnimator/fengari