Fix GC bug in FuncCOMPONENTS_TRANS

The call to `NEW_PLIST` can cause a garbage collection, which would
render the `seen` pointer returned by `ResizeInitTmpTrans` invalid.

Also simplify some similar (but not buggy) code in
`FuncIMAGE_SET_TRANS_INT`

Fixes #2333

src/trans.c

@@ -1185,9 +1185,8 @@ Obj FuncIMAGE_SET_TRANS_INT(Obj self, Obj f, Obj n)
  return new;
  }
  else if (m < deg) {
- pttmp = ResizeInitTmpTrans(deg);
  new = NEW_PLIST_IMM(T_PLIST_CYC, m);
- pttmp = ADDR_TRANS4(TmpTrans);
+ pttmp = ResizeInitTmpTrans(deg);
 
  if (TNUM_OBJ(f) == T_TRANS2) {
  ptf2 = CONST_ADDR_TRANS2(f);
@@ -2900,8 +2899,8 @@ Obj FuncCOMPONENTS_TRANS(Obj self, Obj f)
  return out;
  }
 
- seen = ResizeInitTmpTrans(deg);
  out = NEW_PLIST(T_PLIST, 1);
+ seen = ResizeInitTmpTrans(deg);
  nr = 0;
 
  if (TNUM_OBJ(f) == T_TRANS2) {