Add Breakpad toolchain testing tool

[slipher]

Test that we can get a usable stack trace from our native and/or NaCl binaries. There are two modes:

• Test the whole thing end-to-end: symbolize the binaries, crash them, and get the stack trace.
• Use a release's symbol zip: only do the crash and stack trace.

For Windows there is a capability to run Breakpad binaries within a WSL VM because there is no way to get a native Windows binary that can symbolize NaCl.

Ignore the individual commits, they will be squashed.