Support IntOrString for c client (#216)

openapi/c.xml

@@ -27,6 +27,7 @@
                                 <packageVersion>${generator.client.version}</packageVersion>
                             </configOptions>
                             <output>${generator.output.path}</output>
+                            <typeMappings>int-or-string=IntOrString</typeMappings>
                         </configuration>
                     </execution>
                 </executions>

openapi/preprocess_spec.py

@@ -239,6 +239,8 @@ def preserved_primitives_for_language(client_language):
         # Checking with the prefix because there are variations of
         # typescript generators (e.g. typescript-fetch, typescript-jquery).
         return ["intstr.IntOrString"]
+    elif client_language == "c":
+        return ["intstr.IntOrString"]
     else:
         return []