MinidumpYAML: add support for the ThreadList stream

Summary:
The implementation is a pretty straightforward extension of the pattern
used for (de)serializing the ModuleList stream. Since there are other
streams which use the same format (MemoryList and MemoryList64, at
least). I tried to generalize the code a bit so that adding future
streams of this type can be done with less code.

Reviewers: amccarth, jhenderson, clayborg

Subscribers: markmentovai, lldb-commits, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D61423

llvm-svn: 360350