Make `intern_lazy_const` actually intern its argument.
Currently it just unconditionally allocates it in the arena.
For a "Clean Check" build of the the `packed-simd` benchmark, this
change reduces both the `max-rss` and `faults` counts by 59%; it
slightly (~3%) increases the instruction counts but the `wall-time` is
unchanged.
For the same builds of a few other benchmarks, `max-rss` and `faults`
drop by 1--5%, but instruction counts and `wall-time` changes are in the
noise.
Fixes#57432, fixes#57829.
Currently it just unconditionally allocates it in the arena.
For a "Clean Check" build of the the `packed-simd` benchmark, this
change reduces both the `max-rss` and `faults` counts by 59%; it
slightly (~3%) increases the instruction counts but the `wall-time` is
unchanged.
For the same builds of a few other benchmarks, `max-rss` and `faults`
drop by 1--5%, but instruction counts and `wall-time` changes are in the
noise.
Fixes#57432, fixes#57829.
This seemed like a good way to kick the tires on the
elided-lifetimes-in-paths lint (#52069)—seems to work! This was also
pretty tedious—it sure would be nice if `cargo fix` worked on this
codebase (#53896)!
