Prefer using 'override' instead of 'virtual'

warning: prefer using 'override' or (rarely) 'final' instead of
'virtual' [modernize-use-override]

Change-Id: I6dac7a62b627fa1353b4455e1af92f869c2571cc
Reviewed-by: Marco Benelli <marco.benelli@qt.io>

src/plugins/qmljstools/qmljssemanticinfo.cpp

@@ -86,7 +86,7 @@ protected:
         return handle(ast, ast->firstSourceLocation(), ast->lastSourceLocation(), addToPath);
     }
 
-    virtual bool preVisit(AST::Node *node)
+    bool preVisit(AST::Node *node) override
     {
         if (Statement *stmt = node->statementCast())
             return handleLocationAst(stmt);
@@ -97,7 +97,7 @@ protected:
         return true;
     }
 
-    virtual bool visit(AST::UiQualifiedId *ast)
+    bool visit(AST::UiQualifiedId *ast) override
     {
         AST::SourceLocation first = ast->identifierToken;
         AST::SourceLocation last;
@@ -108,19 +108,19 @@ protected:
         return false;
     }
 
-    virtual bool visit(AST::UiProgram *ast)
+    bool visit(AST::UiProgram *ast) override
     {
         _path.append(ast);
         return true;
     }
 
-    virtual bool visit(AST::Program *ast)
+    bool visit(AST::Program *ast) override
     {
         _path.append(ast);
         return true;
     }
 
-    virtual bool visit(AST::UiImport *ast)
+    bool visit(AST::UiImport *ast) override
     {
         return handleLocationAst(ast);
     }