Release note updates for 7.8.3

Signed-off-by: Austin Seipp <austin@well-typed.com>

docs/users_guide/7.8.3-notes.xml

@@ -17,6 +17,19 @@
             crash during compilation has been fixed (issue #9155).
           </para>
        </listitem>
+       <listitem>
+          <para>
+            A handful of bugs in the pattern synonyms implementation
+            have been fixed (issues #9161, #8966, #9023, #9175).
+          </para>
+       </listitem>
+       <listitem>
+          <para>
+            A bug in runtime system which would cause
+            <literal>tryReadMVar</literal> to deadlock has been fixed
+            (issue #9148).
+          </para>
+       </listitem>
        <listitem>
           <para>
             A segmentation fault for compiled programs using
@@ -36,6 +49,12 @@
             faults has been fixed (issue #9001).
           </para>
        </listitem>
+       <listitem>
+          <para>
+            A bug in the code generator that could cause segmentation
+            faults has been fixed (issue #9045).
+          </para>
+       </listitem>
        <listitem>
           <para>
             A bug which caused <literal>gcc</literal> to error when
@@ -43,6 +62,13 @@
             (issue #8768).
           </para>
        </listitem>
+       <listitem>
+          <para>
+            A bug which caused a performance regression in the new
+            `Typeable` implementation (due to recomputation of known
+            values) has been fixed (issue #9203).
+          </para>
+       </listitem>
        <listitem>
           <para>
             Several memory leaks and bugs in the runtime system and C
@@ -57,6 +83,14 @@
             #9068).
           </para>
        </listitem>
+       <listitem>
+          <para>
+            A bug which could result in programs using all available
+            memory, due to a regression in the <literal>Read</literal>
+            instance for <literal>Data.Fixed.Pico</literal> has been
+            fixed (issue #9231).
+          </para>
+       </listitem>
        <listitem>
           <para>
             The libraries <literal>haskeline</literal>,