Changed code generation for form classes to do a Qt version check

Change-Id: I20200303ef68bc3e73b232c44263d71d09b091a5
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@nokia.com>
Reviewed-by: Bill King <bill.king@nokia.com>

src/libs/utils/codegeneration.h

@@ -55,6 +55,8 @@ void writeIncludeFileDirective(const QString &file,
                                bool globalInclude,
                                QTextStream &str);
 
+QTCREATOR_UTILS_EXPORT void writeBeginQtVersionCheck(QTextStream &str);
+
 // Write opening namespaces and return an indentation string to be used
 // in the following code if there are any.
 QTCREATOR_UTILS_EXPORT