In order for rules to collect arbitrary information about all files
being linted, a shared RuleStorage instance is defined in each command
and passed into the linter.
Linting now requires two "passes": once to call collect and populate the
storage (rules that are non-collecting do nothing here), and again to
call validate. The old Linter factory now creates a Prelinter, which can
collect for a file and produce a Linter that orchestrates all the
traditional validation/collection logic.
This design enforces that a file is only validated once it has been
collected; in turn, the file-visiting loop ensures that all files are
collected before the first is validated, so that the storage is fully
populated.
Use storage-backed correct method
Crash if storage for a rule is accessed prematurely
Key FileInfo by File
Rename Prelinter to Linter and Linter to CollectedLinter
Clean up rule protocols such that rule-facing storage methods are actually called
Make RuleStorage a reference type to solve mutating data races