changes.src: document removal of DREX instructions

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
diff --git a/doc/changes.src b/doc/changes.src
index e56e39d..dcf7c08 100644
--- a/doc/changes.src
+++ b/doc/changes.src
@@ -8,7 +8,7 @@
 since 2007.
 
 
-\S{cl-2.08rc2} Version 2.08rc2
+\S{cl-2.08} Version 2.08
 
 \b A number of enhancements/fixes in macros area.
 
@@ -39,6 +39,9 @@
 
 \b Warn a user if a constant too long (and as a result will be stripped).
 
+\b The obsoleted pre-XOP AMD SSE5 instruction set which was never actualized
+  was removed.
+
 
 \S{cl-2.07} Version 2.07