[llvm] [Clang] Fill in documentation gaps for some attributes (PR #68967)

[Stephen Tozer via llvm-commits]

https://github.com/SLTozer created https://github.com/llvm/llvm-project/pull/68967

This patch adds some missing documentation for some attributes in BitCodeFormat, where the integer code mappings for attributes after code 79 were not listed, and in LangRef where the incompatibility between minsize/optsize and optnone was not mentioned.

>From 8ec4fa7797658d13653bb8dfe9ca856a9d528d76 Mon Sep 17 00:00:00 2001
From: Stephen Tozer <Stephen.Tozer at Sony.com>
Date: Fri, 13 Oct 2023 10:29:23 +0100
Subject: [PATCH] [Clang] Fill in documentation gaps for some attributes

This patch adds some missing documentation for some attributes in
BitCodeFormat, where the integer code mappings for attributes after
code 79 were not listed, and in LangRef where the incompatibility
between minsize/optsize and optnone was not mentioned.
---
 llvm/docs/BitCodeFormat.rst | 8 ++++++++
 llvm/docs/LangRef.rst       | 2 ++
 2 files changed, 10 insertions(+)

diff --git a/llvm/docs/BitCodeFormat.rst b/llvm/docs/BitCodeFormat.rst
index 70be73abef19d6d..db913f59d691d71 100644
--- a/llvm/docs/BitCodeFormat.rst
+++ b/llvm/docs/BitCodeFormat.rst
@@ -1085,6 +1085,14 @@ The integer codes are mapped to well-known attributes as follows.
 * code 77: ``elementtype``
 * code 78: ``disable_sanitizer_instrumentation``
 * code 79: ``nosanitize_bounds``
+* code 80: ``allocalign``
+* code 81: ``allocptr``
+* code 82: ``allockind``
+* code 83: ``presplitcoroutine``
+* code 84: ``fn_ret_thunk_extern``
+* code 85: ``skipprofile``
+* code 86: ``memory``
+* code 87: ``nofpclass``
 
 .. note::
   The ``allocsize`` attribute has a special encoding for its arguments. Its two
diff --git a/llvm/docs/LangRef.rst b/llvm/docs/LangRef.rst
index f542e70bcfee810..f84a86e06e734ba 100644
--- a/llvm/docs/LangRef.rst
+++ b/llvm/docs/LangRef.rst
@@ -1872,6 +1872,7 @@ example:
     passes make choices that keep the code size of this function as small
     as possible and perform optimizations that may sacrifice runtime
     performance in order to minimize the size of the generated code.
+    This attribute is incompatible with the ``optnone`` attribute.
 ``naked``
     This attribute disables prologue / epilogue emission for the
     function. This can have very system-specific consequences.
@@ -2044,6 +2045,7 @@ example:
     passes make choices that keep the code size of this function low,
     and otherwise do optimizations specifically to reduce code size as
     long as they do not significantly impact runtime performance.
+    This attribute is incompatible with the ``optnone`` attribute.
 ``"patchable-function"``
     This attribute tells the code generator that the code
     generated for this function needs to follow certain conventions that