[analyzer] Make VLA checker taint aware. 

Also, slightly modify the diagnostic message in ArrayBound and DivZero (still use 'taint', which might not mean much to the user, but plan on changing it later).

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@148626 91177308-0d34-0410-b5e6-96231b3b80d8
4 files changed