[ARM] Release notes for the Custom Datapath Extension (CDE)

Summary:
This change mentions CDE assembly in the LLVM release notes and CDE
intrinsics in both Clang and LLVM release notes.

Reviewers: kristof.beyls, simon_tatham

Reviewed By: kristof.beyls

Subscribers: danielkiss, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D78481

Author: miyuki

clang/docs/ReleaseNotes.rst

@@ -61,6 +61,8 @@ Non-comprehensive list of changes in this release
   v8.1-M MVE instruction set. ``<arm_mve.h>`` supports the complete API defined
   in the Arm C Language Extensions.
 
+- For the ARM target, C-language intrinsics <arm_cde.h> for the CDE instruction
+  set are now provided.
 
 * clang adds support for a set of  extended integer types (``_ExtInt(N)``) that
   permit non-power of 2 integers, exposing the LLVM integer types. Since a major

llvm/docs/ReleaseNotes.rst

@@ -76,6 +76,11 @@ During this release ...
   set. ``<arm_mve.h>`` now supports the complete API defined in the Arm C
   Language Extensions.
 
+* Added support for assembly for the optional Custom Datapath Extension (CDE)
+  for Arm M-profile targets.
+
+* Implemented C-language intrinsics <arm_cde.h> for the CDE instruction set.
+
 Changes to the MIPS Target
 --------------------------