* Upgrade from u8 to usize element types.
- WebAssembly assumes u64. It should probably try to be target-aware
instead.
* Move the covered PC bits to after the header so it goes on the same
page with the other rapidly changing memory (the header stats).
depends on the semantics of accepted proposal #19755closes#20994
* libfuzzer: track unique runs instead of deduplicated runs
- easier for consumers to notice when to recheck the covered bits.
* move common definitions to `std.Build.Fuzz.abi`.
build runner sends all the information needed to fuzzer web interface
client needed in order to display inline coverage information along with
source code.