rust-index: improve phase computation speed...
rust-index: improve phase computation speed
While less memory efficient, using an array is *much* faster than using a
HashMap, especially with the default hasher. It even makes the code simpler,
so I'm not really sure what I was thinking in the first place, maybe it's more
obvious now.
This fix a significant performance regression when using the rust version of the
code. (however, the C code still outperform rust on this operation)
hg perf::phases on mozilla-try-2023-03-22
- 6.6.3: 0.451239 seconds
- before: 0.982495 seconds
- after: 0.265347 seconds
- C code: 0.183241 second
