[turbopack] const-ify most of the registration code (#90868)
# What
Make a significant chunk of the remaining turbotask registration code
(Values, Traits and Value/Trait impls) `const`. The vtable lookup for
trait methods is constructed at compile time, allowing us to look up a
trait's implementation in near-constant time.
Introduces a new, common RegistryType we use for Values, Traits and
Functions to reduce duplication. We still have a Lazy guard on each
registry, but that will probably be removed if we migrate to distributed
slices.
NOTE: This removes a number of Lazy guards, but not all of them to avoid
making the PR too large. The next pass of PR will remove the remaining
Lazy guards, where possible.
# Why
By making this code `const`, we reduce the overall init time of the
executable, make LTO a little more powerful (when we end up using that),
reduce startup allocations, and reduce the amount of time we spend
checking Lazy atomics.
In hyperfine tests of the benchmark-apps folder, we see a 1% to 3%
speedup for compilation.
