dev/lldb-smoker: LLDB smoke test using NIO (#1840)
dev/lldb-smoker: LLDB smoke test using NIO (#1840)

Motivation:

We often hit a bunch of problems with LLDB, especially on Linux. So
maybe it would be cool if we could smoke test LLDB using SwiftNIO.

Modifications:

Add script `dev/lldb-smoker` which does the following things:

- takes 2000 random picks amongst all the files in the package
- for each of those files, pick a random line number
- write an LLDB script which sets break points for each of the file/line
  pairs (one-shot breakpoints)
- runs the program
- for each breakpoint hit, run `frame variable` to list all the
  variables

Result:

LLDB smoke test
apple/swift-nio,apple/swift-nio,apple/swift-nio,apple/swift-nio,apple/swift-nio