[Ada] Note that hardening features are experimental

[Pierre-Marie de Rodat via Gcc-patches]

Some features haven't got customer feedback or made upstream yet.

Tested on x86_64-pc-linux-gnu, committed on trunk

gcc/ada/

        * doc/gnat_rm/security_hardening_features.rst: Note that hardening
        features are experimental.
        * gnat_rm.texi: Regenerate.
diff --git a/gcc/ada/doc/gnat_rm/security_hardening_features.rst b/gcc/ada/doc/gnat_rm/security_hardening_features.rst
--- a/gcc/ada/doc/gnat_rm/security_hardening_features.rst
+++ b/gcc/ada/doc/gnat_rm/security_hardening_features.rst
@@ -7,6 +7,9 @@ Security Hardening Features
 This chapter describes Ada extensions aimed at security hardening that
 are provided by GNAT.
 
+The features in this chapter are currently experimental and subject to
+change.
+
 .. Register Scrubbing:
 
 Register Scrubbing


diff --git a/gcc/ada/gnat_rm.texi b/gcc/ada/gnat_rm.texi
--- a/gcc/ada/gnat_rm.texi
+++ b/gcc/ada/gnat_rm.texi
@@ -28878,6 +28878,9 @@ RM References:  H.04 (8/1)
 This chapter describes Ada extensions aimed at security hardening that
 are provided by GNAT.
 
+The features in this chapter are currently experimental and subject to
+change.
+
 @c Register Scrubbing:
 
 @menu