Add 2.2.7; update links in 1.2

Signed-off-by: Bill Schmidt <wschmidt@linux.ibm.com>

specification/ch_1.xml

@@ -213,6 +213,8 @@
 	  a TOC pointer for such accesses.  The ABI has been updated to
 	  describe the implications of this new capability.  For specifics,
 	  see <xref linkend="dbdoclet.50655241_FnLinkage" />, <xref
+	  linkend="dbdoclet.50655240___codealign" />, <xref
+	  linkend="dbdoclet.50655240___tailcall" />, <xref
 	  linkend="dbdoclet.50655240___RefHeading___Toc377640591" />, <xref
 	  linkend="dbdoclet.50655241_18894" />, <xref
 	  linkend="dbdoclet.50655241_LinkerOpts" />, <xref

specification/ch_2.xml

@@ -6637,6 +6637,20 @@ s6            -           72 (stored)</programlisting>
         </listitem>
       </itemizedlist>
     </section>
+    <section xml:id="dbdoclet.50655240___codealign"
+	     revisionflag="added">
+      <title>Code Alignment</title>
+      <para>
+	Functions must be aligned on at least a 4-byte boundary.
+      </para>
+      <para>
+	If a function contains any prefixed (8-byte) instructions,
+	functions must be aligned on at least a 64-byte boundary.
+	This is necessary so that compilers and assemblers can avoid
+	placing a prefixed instruction so that it crosses a 64-byte
+	boundary.
+      </para>
+    </section>
     <section xml:id="dbdoclet.50655240___tailcall"
 	     revisionflag="added">
       <title>Tail-Call Optimization</title>