[PATCH] Fix PR19657 : SLP vectorization doesn't combine scalar load to vector loads

[Nadav Rotem]

I am sorry but this is the wrong approach. You copy a ton of code that we will need to maintain if we want to add support to new instructions.

You also increase the compile time by scanning the tree twice. In the SLP vectorizer there are a bunch of features we did not implement because we did not want to increase  compile time. Remember that we run this pass on all optimization levels.

http://reviews.llvm.org/D3800