Add param validation to typedef function pointers

Currently typedef'd function pointers, typically used as callbacks,
don't have their `@param` documentation properly validated. This commit
adds a proper check by initializing their memberdef with the parsed
args. To avoid duplicating the params in the output, since typedef's
already have the params in their definition, an extra check was added.

Signed-off-by: Fabio Utzig <fabio.utzig@nordicsemi.no>

src/doxygen.cpp

@@ -2351,7 +2351,7 @@ static MemberDef *addVariableToFile(
       type,name,args,0,
       root->protection, Normal,root->stat,Member,
       mtype,!root->tArgLists.empty() ? root->tArgLists.back() : ArgumentList(),
-      ArgumentList(), root->metaData) };
+      root->argList, root->metaData) };
   md->setTagInfo(root->tagInfo());
   md->setMemberSpecifiers(root->spec);
   md->setDocumentation(root->doc,root->docFile,root->docLine);

src/memberdef.cpp

@@ -845,7 +845,7 @@ static bool writeDefArgumentList(OutputList &ol,const Definition *scope,const Me
   const ArgumentList &defArgList=(md->isDocsForDefinition()) ?
                              md->argumentList() : md->declArgumentList();
   //printf("writeDefArgumentList '%s' isDocsForDefinition()=%d\n",md->name().data(),md->isDocsForDefinition());
-  if (!defArgList.hasParameters() || md->isProperty())
+  if (!defArgList.hasParameters() || md->isProperty() || md->isTypedef())
   {
     return FALSE; // member has no function like argument list
   }