Update documentation with regards to template type diffing.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@159249 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/docs/InternalsManual.html b/docs/InternalsManual.html
index ca870c4..c97acd1 100644
--- a/docs/InternalsManual.html
+++ b/docs/InternalsManual.html
@@ -357,6 +357,11 @@
 <tr><td>Example:</td><td><tt>"candidate found by name lookup is %q0"</tt></td></tr>
 <tr><td>Class:</td><td>NamedDecl*</td></tr>
 <tr><td>Description</td><td><p>This formatter indicates that the fully-qualified name of the declaration should be printed, e.g., "std::vector" rather than "vector".</p></td></tr>
+
+<tr><td colspan="2"><b>"diff" format</b></td></tr>
+<tr><td>Example:</td><td><tt>"no known conversion %diff{from | to | }1,2"</tt></td></tr>
+<tr><td>Class:</td><td>QualType</td></tr>
+<tr><td>Description</td><td><p>This formatter takes two QualTypes and attempts to print a template difference between the two.  If tree printing is off, the entire text inside the the braces, with the formatted text replacing the pipes.  If tree printing is on, the text is not printed and a type tree is printed after the diagnostic message.</p></td></tr>
     
 </table>