[clang] [llvm] Reapply "[clang][ssaf] Add --ssaf-extract-summaries= and --ssaf-tu-summary-file= options" (PR #186463)

[Ziqing Luo via cfe-commits]

================
@@ -0,0 +1,28 @@
+//===- SSAFBuiltinForceLinker.h ---------------------------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+///
+/// \file
+/// This file pulls in all built-in SSAF extractor and format registrations
----------------
ziqingluo-90 wrote:

Trying to get this clear in my head:
- why do we need both `SSAFBuiltinForceLinker.h` and `SSAFForceLinker.h`?
- For extractors in plugins, we do not need an anchor there, right?

https://github.com/llvm/llvm-project/pull/186463