[clang] [llvm] [llvm][clang] Move RewriterBuffer to ADT. (PR #99770)

[LLVM Continuous Integration via cfe-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `lld-x86_64-win` running on `as-worker-93` while building `clang,llvm` at step 7 "test-build-unified-tree-check-all".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/146/builds/477

Here is the relevant piece of the build log for the reference:
```
Step 7 (test-build-unified-tree-check-all) failure: test (failure)
******************** TEST 'LLVM-Unit :: Support/./SupportTests.exe/41/86' FAILED ********************
Script(shard):
--
GTEST_OUTPUT=json:C:\a\lld-x86_64-win\build\unittests\Support\.\SupportTests.exe-LLVM-Unit-13204-41-86.json GTEST_SHUFFLE=0 GTEST_TOTAL_SHARDS=86 GTEST_SHARD_INDEX=41 C:\a\lld-x86_64-win\build\unittests\Support\.\SupportTests.exe
--

Script:
--
C:\a\lld-x86_64-win\build\unittests\Support\.\SupportTests.exe --gtest_filter=ProgramEnvTest.CreateProcessLongPath
--
C:\a\lld-x86_64-win\llvm-project\llvm\unittests\Support\ProgramTest.cpp(160): error: Expected equality of these values:
  0
  RC
    Which is: -2

C:\a\lld-x86_64-win\llvm-project\llvm\unittests\Support\ProgramTest.cpp(163): error: fs::remove(Twine(LongPath)): did not return errc::success.
error number: 13
error message: permission denied



C:\a\lld-x86_64-win\llvm-project\llvm\unittests\Support\ProgramTest.cpp:160
Expected equality of these values:
  0
  RC
    Which is: -2

C:\a\lld-x86_64-win\llvm-project\llvm\unittests\Support\ProgramTest.cpp:163
fs::remove(Twine(LongPath)): did not return errc::success.
error number: 13
error message: permission denied




********************


```

https://github.com/llvm/llvm-project/pull/99770