[clang-tools-extra] [include-cleaner] Handle non-self-contained includes. (PR #185495)

[via cfe-commits]

github-actions[bot] wrote:

<!--PREMERGE ADVISOR COMMENT: Windows-->
# :window: Windows x64 Test Results

* 3103 tests passed
* 29 tests skipped
* 1 test failed

## Failed Tests
(click on a test name to see its output)

### clangIncludeCleaner Unit Tests
<details>
<summary>clangIncludeCleaner Unit Tests._/ClangIncludeCleanerTests_exe/RecordASTTest/ImplicitTemplates</summary>

```
Script:
--
C:\_work\llvm-project\llvm-project\build\tools\clang\tools\extra\include-cleaner\unittests\.\ClangIncludeCleanerTests.exe --gtest_filter=RecordASTTest.ImplicitTemplates
--
C:\_work\llvm-project\llvm-project\clang-tools-extra\include-cleaner\unittests\RecordTest.cpp:163
Value of: Recorded.Roots
Expected: has 2 elements where
element #0 named (N: "MyGetter"),
element #1 named (N: "v")
  Actual: { 000002846EC2C000, 000002846EC2C4A0, 000002846EC2C718, 000002846EC2CB90 }, which has 4 elements


```
</details>

If these failures are unrelated to your changes (for example tests are broken or flaky at HEAD), please open an issue at https://github.com/llvm/llvm-project/issues and add the `infrastructure` label.

https://github.com/llvm/llvm-project/pull/185495