QmlJS: Keep pragma directive when reformatting QML files

Change-Id: I1f11e95565a90e4fc7b908c03d49f6abbd37b8be
Reviewed-by: Marco Benelli <marco.benelli@qt.io>

src/libs/qmljs/qmljsreformatter.cpp

@@ -480,6 +480,13 @@ protected:
         }
     }
 
+    virtual bool visit(UiPragma *ast)
+    {
+        out("pragma ", ast->pragmaToken);
+        accept(ast->pragmaType);
+        return false;
+    }
+
     virtual bool visit(UiImport *ast)
     {
         out("import ", ast->importToken);
@@ -1187,6 +1194,12 @@ protected:
         return false;
     }
 
+    virtual bool visit(UiQualifiedPragmaId *ast)
+    {
+        out(ast->identifierToken);
+        return false;
+    }
+
     virtual bool visit(Elision *ast)
     {
         for (Elision *it = ast; it; it = it->next) {

tests/auto/qml/reformatter/qmlsingleton.qml

@@ -0,0 +1,6 @@
+pragma Singleton
+
+import QtQuick 2.0
+
+Item {
+}