[Bug c/60439] No warning for case overflow in switch statement.

[gary at intrepid dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=60439

--- Comment #12 from Gary Funck <gary at intrepid dot com> ---
I submitted Bug #61480 documenting the interaction between Var() and Init().

The test case that I posted is abstracted from actual code.  As far as which
switches should be default and/or enabled by -Wall, that question probably
needs further review.