Add -Werror -Wshadow compiler flags to CMAKE_CXX_FLAGS (#531)

[vaezim]

No description provided.

[rh101]

@vaezim It looks like you accidentally changed code completely unrelated to the -Werror -Wshadow compiler flags. There shouldn't be underscores at the start of all those variable names.

[vaezim]

@vaezim It looks like you accidentally changed code completely unrelated to the -Werror -Wshadow compiler flags. There shouldn't be underscores at the start of all those variable names.

Those variables were shadowed by another variable in the outer scopes. Either outer scope variable or local ones needed renaming. Do you have other solutions? we can clear the outer one and reuse it.

[rh101]

Those variables were shadowed by another variable in the outer scopes. Either outer scope variable or local ones needed renaming. Do you have other solutions? we can clear the outer one and reuse it.

If that's the case, then it would be best to rename them to something more appropriate, without the underscore prefix, since by convention that makes them appear as class member variables, which they are not.

If it is possible to re-use the outer-scope variables, then that is also a solution, but all code paths should be considered to ensure it is safe to re-use them.

[vaezim]

Removed underscores and renamed according to scope context.