A new crash reporter for Firefox

On April 23, Mozillaannounced that Firefox's crash reporter has been rewritten in Rust, allowing theproject to address a backlog of issues.

Even though it is important to properly handle main process crashes, the crashreporter hasn't received significant development in a while (aside fromdevelopment to ensure that crash reports and telemetry continue to reliably bedelivered)! It has long been stuck in a local maximum of "good enough" and"scary to maintain": it features 3 individual GUI implementations (for Windows,GTK+ for Linux, and macOS), glue code abstracting a few things (mostly in C++,and Objective-C for macOS), a binary blob produced by obsoleted Appledevelopment tools, and no test suite. Because of this, there is a backlog offeatures and improvements which haven't been acted on.