[analyzer] bugreporter::getDerefExpr now takes a Stmt, not an ExplodedNode.

This allows it to be used in places where the interesting statement
doesn't match up with the current node. No functionality change.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@173546 91177308-0d34-0410-b5e6-96231b3b80d8
3 files changed