Add the optional 'superOnly' request parameter for 'search.getTypeHierarchy'.

pkg/analysis_server/tool/spec/spec_input.html

Index: pkg/analysis_server/tool/spec/spec_input.html
diff --git a/pkg/analysis_server/tool/spec/spec_input.html b/pkg/analysis_server/tool/spec/spec_input.html
index c8b8c3a11dcad555ad65238789488a2b731cce75..974eb977151d5a6782f5b5247a7a78ac85f9cd28 100644
--- a/pkg/analysis_server/tool/spec/spec_input.html
+++ b/pkg/analysis_server/tool/spec/spec_input.html
@@ -1308,6 +1308,13 @@
               The offset of the name of the type within the file.
             </p>
           </field>
+          <field name="superOnly" optional="true">
+            <ref>bool</ref>
+            <p>
+              True if the client is only requesting superclasses and
+              interfaces hierarchy.
+            </p>
+          </field>
         </params>
         <result>
           <field name="hierarchyItems" optional="true">