[Clang][docs] Update the release notes page to the new skeleton

Was discussed at https://reviews.llvm.org/D142578.

clang/docs/ReleaseNotes.rst

@@ -13,7 +13,7 @@ Written by the `LLVM Team <https://llvm.org/>`_
   .. warning::
      These are in-progress notes for the upcoming Clang |version| release.
      Release notes for previous releases can be found on
-     `the Download Page <https://releases.llvm.org/download.html>`_.
+     `the Releases Page <https://llvm.org/releases>`_.
 
 Introduction
 ============
@@ -23,59 +23,59 @@ frontend, part of the LLVM Compiler Infrastructure, release |release|. Here we
 describe the status of Clang in some detail, including major
 improvements from the previous release and new feature work. For the
 general LLVM release notes, see `the LLVM
-documentation <https://llvm.org/docs/ReleaseNotes.html>`_. All LLVM
-releases may be downloaded from the `LLVM releases web
-site <https://llvm.org/releases/>`_.
+documentation <https://llvm.org/docs/ReleaseNotes.html>`_. For the libc++ release notes,
+see `this page <https://libcxx.llvm.org/ReleaseNotes.html>`_. All LLVM releases
+may be downloaded from the `LLVM releases web site <https://llvm.org/releases/>`_.
 
 For more information about Clang or LLVM, including information about the
 latest release, please see the `Clang Web Site <https://clang.llvm.org>`_ or the
 `LLVM Web Site <https://llvm.org>`_.
 
-Note that if you are reading this file from a Git checkout or the
-main Clang web page, this document applies to the *next* release, not
-the current one. To see the release notes for a specific release, please
-see the `releases page <https://llvm.org/releases/>`_.
-
 Potentially Breaking Changes
 ============================
 These changes are ones which we think may surprise users when upgrading to
 Clang |release| because of the opportunity they pose for disruption to existing
 code bases.
 
+
+C/C++ Language Potentially Breaking Changes
+-------------------------------------------
+
+C++ Specific Potentially Breaking Changes
+-----------------------------------------
+
+ABI Changes in This Version
+---------------------------
+
 What's New in Clang |release|?
 ==============================
 Some of the major new features and improvements to Clang are listed
 here. Generic improvements to Clang as a whole or to its underlying
 infrastructure are described first, followed by language-specific
 sections with improvements to Clang's support for those languages.
 
-Major New Features
-------------------
+C++ Language Changes
+--------------------
+- Improved ``-O0`` code generation for calls to ``std::forward_like``. Similarly to
+  ``std::move, std::forward`` et al. it is now treated as a compiler builtin and implemented
+  directly rather than instantiating the definition from the standard library.
 
-Bug Fixes
----------
-- Fix crash on invalid code when looking up a destructor in a templated class
-  inside a namespace. This fixes
-  `Issue 59446 <https://github.com/llvm/llvm-project/issues/59446>`_.
-- Fix crash when diagnosing incorrect usage of ``_Nullable`` involving alias
-  templates. This fixes
-  `Issue 60344 <https://github.com/llvm/llvm-project/issues/60344>`_.
-- Fix confusing warning message when ``/clang:-x`` is passed in ``clang-cl``
-  driver mode and emit an error which suggests using ``/TC`` or ``/TP``
-  ``clang-cl`` options instead. This fixes
-  `Issue 59307 <https://github.com/llvm/llvm-project/issues/59307>`_.
-- Fix crash when evaluating consteval constructor of derived class whose base
-  has more than one field. This fixes
-  `Issue 60166 <https://github.com/llvm/llvm-project/issues/60166>`_.
+C++20 Feature Support
+^^^^^^^^^^^^^^^^^^^^^
 
-Improvements to Clang's diagnostics
-^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
-- We now generate a diagnostic for signed integer overflow due to unary minus
-  in a non-constant expression context. This fixes
-  `Issue 31643 <https://github.com/llvm/llvm-project/issues/31643>`_
-- Clang now warns by default for C++20 and later about deprecated capture of
-  ``this`` with a capture default of ``=``. This warning can be disabled with
-  ``-Wno-deprecated-this-capture``.
+C++2b Feature Support
+^^^^^^^^^^^^^^^^^^^^^
+
+Resolutions to C++ Defect Reports
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+C Language Changes
+------------------
+
+C2x Feature Support
+^^^^^^^^^^^^^^^^^^^
+- Implemented the ``unreachable`` macro in freestanding ``<stddef.h>`` for
+  `WG14 N2826 <https://www.open-std.org/jtc1/sc22/wg14/www/docs/n2826.pdf>`_
 
 Non-comprehensive list of changes in this release
 -------------------------------------------------
@@ -97,114 +97,114 @@ Modified Compiler Flags
 Removed Compiler Flags
 -------------------------
 
-New Pragmas in Clang
---------------------
-- ...
-
 Attribute Changes in Clang
 --------------------------
+- Introduced a new function attribute ``__attribute__((unsafe_buffer_usage))``
+  to be worn by functions containing buffer operations that could cause out of
+  bounds memory accesses. It emits warnings at call sites to such functions when
+  the flag ``-Wunsafe-buffer-usage`` is enabled.
+- ``__declspec`` attributes can now be used together with the using keyword. Before
+  the attributes on ``__declspec`` was ignored, while now it will be forwarded to the
+  point where the alias is used.
 
-Introduced a new function attribute ``__attribute__((unsafe_buffer_usage))``
-to be worn by functions containing buffer operations that could cause out of
-bounds memory accesses. It emits warnings at call sites to such functions when
-the flag ``-Wunsafe-buffer-usage`` is enabled.
+Improvements to Clang's diagnostics
+-----------------------------------
+- We now generate a diagnostic for signed integer overflow due to unary minus
+  in a non-constant expression context.
+  (`#31643 <https://github.com/llvm/llvm-project/issues/31643>`)
+- Clang now warns by default for C++20 and later about deprecated capture of
+  ``this`` with a capture default of ``=``. This warning can be disabled with
+  ``-Wno-deprecated-this-capture``.
 
-``__declspec`` attributes can now be used together with the using keyword. Before
-the attributes on ``__declspec`` was ignored, while now it will be forwarded to the
-point where the alias is used.
+Bug Fixes in This Version
+-------------------------
 
-Windows Support
----------------
+- Fix crash when diagnosing incorrect usage of ``_Nullable`` involving alias
+  templates.
+  (`#60344 <https://github.com/llvm/llvm-project/issues/60344>`_)
+- Fix confusing warning message when ``/clang:-x`` is passed in ``clang-cl``
+  driver mode and emit an error which suggests using ``/TC`` or ``/TP``
+  ``clang-cl`` options instead.
+  (`#59307 <https://github.com/llvm/llvm-project/issues/59307>`_)
 
-AIX Support
------------
+Bug Fixes to Compiler Builtins
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-C Language Changes in Clang
----------------------------
+Bug Fixes to Attribute Support
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-C2x Feature Support
--------------------
-- Implemented the ``unreachable`` macro in freestanding ``<stddef.h>`` for
-  `WG14 N2826 <https://www.open-std.org/jtc1/sc22/wg14/www/docs/n2826.pdf>`_
+Bug Fixes to C++ Support
+^^^^^^^^^^^^^^^^^^^^^^^^
 
-C++ Language Changes in Clang
------------------------------
-- Improved ``-O0`` code generation for calls to ``std::forward_like``. Similarly to
-  ``std::move, std::forward`` et al. it is now treated as a compiler builtin and implemented
-  directly rather than instantiating the definition from the standard library.
+- Fix crash on invalid code when looking up a destructor in a templated class
+  inside a namespace.
+  (`#59446 <https://github.com/llvm/llvm-project/issues/59446>`_)
+- Fix crash when evaluating consteval constructor of derived class whose base
+  has more than one field.
+  (`#60166 <https://github.com/llvm/llvm-project/issues/60166>`_)
 
-C++20 Feature Support
-^^^^^^^^^^^^^^^^^^^^^
+Bug Fixes to AST Handling
+^^^^^^^^^^^^^^^^^^^^^^^^^
 
-C++2b Feature Support
-^^^^^^^^^^^^^^^^^^^^^
+Miscellaneous Bug Fixes
+^^^^^^^^^^^^^^^^^^^^^^^
 
-CUDA/HIP Language Changes in Clang
-----------------------------------
+Miscellaneous Clang Crashes Fixed
+^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-Objective-C Language Changes in Clang
--------------------------------------
-
-OpenCL C Language Changes in Clang
-----------------------------------
+Target Specific Changes
+-----------------------
 
-...
+X86 Support
+^^^^^^^^^^^
 
-ABI Changes in Clang
---------------------
+Arm and AArch64 Support
+^^^^^^^^^^^^^^^^^^^^^^^
 
-OpenMP Support in Clang
------------------------
+- The hard-float ABI is now available in Armv8.1-M configurations that
+  have integer MVE instructions (and therefore have FP registers) but
+  no scalar or vector floating point computation. Previously, trying
+  to select the hard-float ABI on such a target (via
+  ``-mfloat-abi=hard`` or a triple ending in ``hf``) would silently
+  use the soft-float ABI instead.
 
-...
+- Clang builtin ``__arithmetic_fence`` and the command line option ``-fprotect-parens``
+  are now enabled for AArch64.
 
-CUDA Support in Clang
----------------------
+Windows Support
+^^^^^^^^^^^^^^^
 
-LoongArch Support in Clang
---------------------------
+LoongArch Support
+^^^^^^^^^^^^^^^^^
 
-RISC-V Support in Clang
------------------------
+RISC-V Support
+^^^^^^^^^^^^^^
 - Added ``-mrvv-vector-bits=`` option to give an upper and lower bound on vector
   length. Valid values are powers of 2 between 64 and 65536. A value of 32
   should eventually be supported. We also accept "zvl" to use the Zvl*b
   extension from ``-march`` or ``-mcpu`` to the be the upper and lower bound.
 
-X86 Support in Clang
---------------------
-
-WebAssembly Support in Clang
-----------------------------
+CUDA/HIP Language Changes
+^^^^^^^^^^^^^^^^^^^^^^^^^
 
-DWARF Support in Clang
-----------------------
+CUDA Support
+^^^^^^^^^^^^
 
-Arm and AArch64 Support in Clang
---------------------------------
+AIX Support
+^^^^^^^^^^^
 
-- The hard-float ABI is now available in Armv8.1-M configurations that
-  have integer MVE instructions (and therefore have FP registers) but
-  no scalar or vector floating point computation. Previously, trying
-  to select the hard-float ABI on such a target (via
-  ``-mfloat-abi=hard`` or a triple ending in ``hf``) would silently
-  use the soft-float ABI instead.
+WebAssembly Support
+^^^^^^^^^^^^^^^^^^^
 
-- Clang builtin ``__arithmetic_fence`` and the command line option ``-fprotect-parens``
-  are now enabled for AArch64.
+DWARF Support in Clang
+----------------------
 
 Floating Point Support in Clang
 -------------------------------
 - Add ``__builtin_elementwise_log`` builtin for floating point types only.
 - Add ``__builtin_elementwise_log10`` builtin for floating point types only.
 - Add ``__builtin_elementwise_log2`` builtin for floating point types only.
 
-Internal API Changes
---------------------
-
-Build System Changes
---------------------
-
 AST Matchers
 ------------
 
@@ -216,9 +216,6 @@ clang-format
   put the initializers on the current line first, instead, it will try to
   put the initializers on the next line only.
 
-clang-extdef-mapping
---------------------
-
 libclang
 --------
 
@@ -234,25 +231,6 @@ Static Analyzer
 Sanitizers
 ----------
 
-Core Analysis Improvements
-==========================
-
-- ...
-
-New Issues Found
-================
-
-- ...
-
-Python Binding Changes
-----------------------
-
-The following methods have been added:
-
--  ...
-
-Significant Known Problems
-==========================
 
 Additional Information
 ======================
@@ -265,5 +243,5 @@ this release by going into the "``clang/docs/``" directory in the Clang
 tree.
 
 If you have any questions or comments about Clang, please feel free to
-contact us on the Discourse forums (Clang Frontend category)
+contact us on the `Discourse forums (Clang Frontend category)
 <https://discourse.llvm.org/c/clang/6>`_.