Issue #352Closes#1720
The old checker would happily accept things like 'alt x { @some(a) { a } }'.
It now properly descends into patterns, checks exhaustiveness of booleans,
and complains when number/string patterns aren't exhaustive.
All the files below had at least one instance of the ternary operator
present in the source. All have been changed to the equivalent
if/then/else expression.
3 tests, pretty/block-disambig.rs, run-pass/operator-overloading.rs,
and run-pass/weird-exprs.rs, all included the ternary operator. These
were changed to use the if-then-else construct instead.
2 tests, run-pass/block-arg-in-ternary.rs and run-pass/ternary.rs, were
only there because of the ternary operator, and were removed.
