Vectorizer/PassManager: I am working on moving the vectorizer out of the SCC...

Vectorizer/PassManager:  I am working on moving the vectorizer out of the SCC passes. This patch moves the SLP-vectorizer and BB-vectorizer back into SCC passes for two reasons:
1. They are a kind of cannonicalization.
2. The performance measurements show that it is better to keep them in.

There should be no functional change if you are not enabling the LateVectorization mode.

llvm-svn: 189539