[Minor perf] Avoid unnecessary allocations

[blyxyas]

Commits:

1. Reserve store.late_passes with 320 and store.early_passes with 64, this leaves us some leeway for adding new passes. Note that there are not as many passes are there lints.
2. Add [env] with some MALLOC_CONF for mainly for faster testing, but to also optimize in profiling.

This PR makes it so we avoid unnecessary reallocations, oh and we now use MALLOC_CONF for some heap-allocation optimization (I tested manually every config flag and came to this conclusion, see jemalloc/TUNING.md). I'm not sure if this would impact on rustup-distributed binaries, but I'm also taking some measures to make sure that rustup-distributed Clippy binaries (and the Rust compiler overall)) use all of Jemalloc

The performance gains vary depending on factors outside of the users control, but in wasmi (my favourite crate to benchmark due to the 66K LOC) it varies between 100ms to 400ms. Overall a solid optimization.

How to test:

There are two ways to benchmark, either with cargo lintcheck --perf in the checkout and in master, then perf diff perf.data perf.data.0, or with RUSTFLAGS="-Zself-profile" cargo dev lint <my_crate>, and measureme. Choose whichever one is most comfortable.

changelog: Minor allocation performance improvements.

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