Log the match substring as well in the case where we match the step-avoid regexp.
Log the match substring as well in the case where we match the step-avoid regexp.

git-svn-id: 4c4cc70b1ef44ba2b7963015e681894188cea27e@177119 91177308-0d34-0410-b5e6-96231b3b80d8

llvm-mirror/lldb,llvm-mirror/lldb,llvm-mirror/lldb,apple/swift-lldb,apple/swift-lldb,llvm-mirror/lldb,apple/swift-lldb,llvm-mirror/lldb,apple/swift-lldb,apple/swift-lldb,apple/swift-lldb