[llvm] ids-check: Update the workflow and script (PR #199710)

[Aiden Grossman via llvm-commits]

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@@ -5,31 +5,270 @@
 # SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 
 import argparse
+import json
 import os
 import subprocess
 import sys
+from collections import defaultdict
+from pathlib import Path
 from typing import List, Optional
 
 """
-This script is run by GitHub actions to ensure that the code in PRs properly
-labels LLVM APIs with `LLVM_ABI` so as not to break the LLVM DLL build. It can
-also be installed as a pre-commit git hook to check ABI annotations before
-submitting. The canonical source of this script is in the LLVM source tree
-under llvm/utils/git.
+Run idt on the headers changed in a PR and (optionally) post the resulting
+LLVM_ABI annotation diff as a PR comment.
 
-This script uses the idt (Interface Diff Tool) to check for missing LLVM_ABI,
-LLVM_C_ABI, and DEMANGLE_ABI annotations in header files.
+The heavy lifting (per-category clang flags, system-header-prefix isolation,
+output filtering, the `hasBody` / out-of-line distinction) lives in
+`llvm/utils/idt/idt.cc`. This script is a thin orchestrator: it picks which
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boomanaiden154 wrote:

This is not a real directory?

https://github.com/llvm/llvm-project/pull/199710