RFR: 8348611: Eliminate DeferredLintHandler and emit warnings after attribution [v5]

[Archie Cobbs]

> This is a cleanup/refactoring of how lint warnings are logged and `@SuppressWarnings` annotations applied.
> 
> A central challenge with lint warnings is that warnings can be generated during any compiler phase, but whether a particular lint warning is suppressed via `@SuppressWarnings` can't be known until after attribution. For example, the parser doesn't have enough information to interpret and apply `@SuppressWarnings("text-blocks")` to text blocks, or `@SuppressWarnings("preview")` to preview lexical features; instead, the `DeferredLintHandler` is used to workaround this limitation.
> 
> In addition, several other factors complicate things:
> * Knowing the current applicable `Lint` instance requires manually tracking it with each declaration visited and applying/removing the `@SuppressWarnings` annotation there, if any
> * Some warnings are "suppressibly mandatory" (i.e., they are _emitted if not suppressed_ instead of _emitted if enabled_)
> * Some warnings are "unsuppressibly mandatory" (e.g., the "internal proprietary API" warning)
> * Some mandatory warnings are _aggregated_ into notes that are emitted at the end of compilation when not enabled
> * Some warnings are _lint_ warnings, with a corresponding lint category, while others are just "plain" warnings
> * Some lint warnings are suppressible via `@SuppressWarnings`, while others are only suppressible via `-Xlint:-foo` flags
> * Speculative compilation requires holding log messages in purgatory until the speculation resolves, after which they are then either discarded or emitted. But this creates a tricky interaction with `DeferredLintHandler` because even after speculation is complete, we may still not yet know whether a warning should be suppressed.
> 
> Previously the logic to get all of this right was non-obviously woven around the code base. In particular, you needed to know somehow whether or not to use `DeferredLintHandler`, and in what "mode".
> 
> The overall goal of this PR is to simplify usage so that **no matter where you are in the compiler, you can just invoke `log.warning()` to log a warning** and (mostly) forget about all of the details listed above.

Archie Cobbs has updated the pull request incrementally with one additional commit since the last revision:

  Refactor LintMapper to clean up internal type hierarchy per review.

-------------

Changes:
  - all: https://git.openjdk.org/jdk/pull/24584/files
  - new: https://git.openjdk.org/jdk/pull/24584/files/d4322d92..f65e1950

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=jdk&pr=24584&range=04
 - incr: https://webrevs.openjdk.org/?repo=jdk&pr=24584&range=03-04

  Stats: 121 lines in 1 file changed: 24 ins; 39 del; 58 mod
  Patch: https://git.openjdk.org/jdk/pull/24584.diff
  Fetch: git fetch https://git.openjdk.org/jdk.git pull/24584/head:pull/24584

PR: https://git.openjdk.org/jdk/pull/24584