What's the best approach to repair a wedge/corner crack in my foundation?
I worked concrete one summer while I was in high school, but I'm no expert and it was a long time ago. That being said, here's what I would try:

I'd give both of your solutions a shot first. However, if you end up completely destroying the two chips, I'd try to pour a new corner. Drill two holes into the corner of the foundation and dowel into it with a few inches of 3/8" re-bar. After you've hammered in the steel, form up the corner and pour the concrete.

Also, this forum includes discussion about how to repair similar cracks.

This website also explains a bit more about this type of foundation crack:


  Brick that is laid directly in contact with concrete foundations can cause angular cracks like this in the top 12 - 16 inches of a foundation. These cracks are caused by the brick expanding and pushing the outer corner of the foundation with it. The cracks are not major structural problems.
  
  It is often pointless to repair them as the next time it gets hot, a crack will likely appear in your repair material.