[OpenSmalltalk/opensmalltalk-vm] a8de82: Fix issue #472

 
  Branch: refs/heads/fix_Squeak3D_Issue472
  Home:   https://github.com/OpenSmalltalk/opensmalltalk-vm
  Commit: a8de821bb8cbed53c40c15c6d536845985423b47
      https://github.com/OpenSmalltalk/opensmalltalk-vm/commit/a8de821bb8cbed53c40c15c6d536845985423b47
  Author: Nicolas Cellier <[hidden email]>
  Date:   2020-01-21 (Tue, 21 Jan 2020)

  Changed paths:
    M platforms/Cross/plugins/Squeak3D/b3dInit.c

  Log Message:
  -----------
  Fix issue #472

when `i == j`, there is nothing to sort.
If we call this for the first time, there is no stack allocated by `INIT(0)`, but stack is accessed nonetheless thru `PUSH(i,j)`.
The best thing todo IMO is to return early.