changes.src: document JMP reg64 fix.

Document the fixed JMP reg64.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
diff --git a/doc/changes.src b/doc/changes.src
index b0f3ab4..dff6f9c 100644
--- a/doc/changes.src
+++ b/doc/changes.src
@@ -10,6 +10,8 @@
 
 \S{cl-2.05} Version 2.05
 
+\b Fix redundant REX.W prefix on \c{JMP reg64}.
+
 \b Make the behaviour of \c{-O0} match NASM 0.98 legacy behavior.
   See \k{opt-O}.