[llvm] [ci] Add ids workflow for checking llvm apis have been annotated with LLVM_ABI (PR #128370)

[Saleem Abdulrasool via llvm-commits]

================
@@ -0,0 +1,95 @@
+name: ids-check
+on:
+  pull_request:
+    types:
+      - opened
+      - synchronize
+      - reopened
+      - closed
+  push:
+    branches:
+      - 'main'
+      - 'release/**'
+
+permissions:
+  contents: read
+
+concurrency:
+  group: ${{ github.workflow }}-${{ github.event.pull_request.number }}
+  cancel-in-progress: true
+
+jobs:
+  build:
+    if: github.repository_owner == 'llvm'
+    name: ids-check
+    runs-on: ubuntu-24.04
----------------
compnerd wrote:

> You still haven't explained why it is important to target Windows. What's the problem with building on Linux for Linux (apart from conditionally compiled code, which will always be missed in one direction or the other)?

The macro expansions are platform specific: Linux doesn't use `__declspec(dllexport)` and `__declspec(dllimport)` which have *different* semantics from `__attribute__((__visibility__(...)))`. We would get close with just a Linux build, but it won't be exact. `ids` basically just parses the source code as if it were the target you specify and then attempts to identify the attributes on the interfaces.

https://github.com/llvm/llvm-project/pull/128370