Paper Submission (OSDI 25) Sprint Improvements

[JustusAdam]

What Changed?

This PR contains a plethora of improvements and fixes performed for the OSDI 25 submission. They should be separate PRs but I am too lazy to make so many.

Why Does It Need To?

This PR fixes the following problems:

• async_trait recognition now accommodates newer versions which sometimes have more than 2 predicates in the dyn
• Writing cross-crate MIR bodies now happens after the analysis and can be skipped. The analysis will lazily fetch and create typecheck facts for local bodies.
• Bodies are now written in a per-crate artifact to reduce size. Filenames contained in those artifacts are deduplicated.
• End-to-end timing (including for cross crate MIR dumping) is now recorded as well as and new timers for dumping of MIR have been added
• For efficiency we no longer construct the polonius facts but use just the outlives constraints directly which turn out to be sufficient
• Shim calls (for function pointers and closures) are now handled correctly
• Fixed control flow across function boundaries. It is now emitted correctly.
• Control flow edges from the await state machine are now omitted from the PDG.
• Artifacts are written (vastly) more efficiently using buffered readers/writers
• External marker files can now assign multiple markers to an entity in a single entry or to multiple refinements.
• PDGs are now always constructed for bodies that handle marked types
• Emitting the spans of analyzed bodies has been reinstated
• Context has been renamed to RootContext and a new Context trait has been introduced that contains some of the simple graph queries.

Checklist

• Above description has been filled out so that upon quash merge we have a
  good record of what changed.
• New functions, methods, types are documented. Old documentation is updated
  if necessary
• Documentation in Notion has been updated
• Tests for new behaviors are provided
  • New test suites (if any) ave been added to the CI tests (in
    .github/workflows/rust.yml) either as compiler test or integration test.
    Or justification for their omission from CI has been provided in this PR
    description.