This works around: https://github.com/ziglang/zig/issues/19148
This lets our `test-valgrind` command catch some issues. We'll have to
follow this pattern in more places but I want to do it incrementally so
things keep passing.
I **do not** want to blindly follow this pattern everywhere. I want to
start by focusing in only on the structs that set `undefined` as default
fields that we're also about to test in isolation with Valgrind. Its
just too much noise otherwise and not a general style I'm sure of; it's
worth it for Valgrind though.
This introduces a new package `src/synthetic` for generating synthetic
data, currently primarily for benchmarking but other use cases can
emerge.
The synthetic package exports a runtime-dispatched type `Generator` that
can generate data of various types. To start, we have a bytes, utf8,
and OSC generator. The goal of each generator is to expose knobs to tune the
probabilities of various outcomes. For example, the UTF-8 generator has
a knob to tune the probability of generating 1, 2, 3, or 4-byte UTF-8
sequences.
Ultimately, the goal is to be able to collect probability data
empirically that we can then use for benchmarks so we can optimize
various parts of the codebase on real-world data shape distributions.
