Logical expressions like `true || false` are now constant folded. This
also allows for dead code elimination if we know the right-hand side of
the expression will never be evaluated (such as `false && f()` or
`true || f()`).
In the test suites, the values are now being constant folded at compile
time. To ensure that the actual evaluation logic is being called
properly, I had to duplicate the tests and call them via a function so
the compiler would not optimize the evaluation logic away.
This also demotes `NaN` and `Infinity` identifiers to `nan` and
`inf` double literals, which will further help with const folding.
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