Hello
This patch introduce a possibility to implement some new checks without
impact to current code.
1. there is a common agreement about this functionality, syntax, naming
2. patching is clean, compilation is without error and warning
3. all regress tests passed
4. feature is well documented
5. code is clean, documented and respect out codding standards
Note: please, replace "shadowed-variables" by "shadowed_variables"
This patch is ready for commit
Regards
Pavel Stehule