ReleaseNotes: mention the machine outliner for ARM

zmodem · zmodem · commit f80e6d634230 · 2020-10-05T13:38:48.000+02:00
As suggested by Yvan.
diff --git a/llvm/docs/ReleaseNotes.rst b/llvm/docs/ReleaseNotes.rst
@@ -165,6 +165,9 @@ Changes to the ARM Backend
 
 * Added support for Cortex-M55, Cortex-A77, Cortex-A78 and Cortex-X1 cores.
 
+* The Machine Outliner is now supported for ARM and Thumb2, it is not
+  turned on by default and can be enabled with the ``-moutline`` clang flag.
+
 
 Changes to the PowerPC Target
 -----------------------------
