The reader now reads the symbolic float values ##Inf, ##-Inf and ##NaN. Added
infinite? and NaN? predicates. Fixed intval? to exclude infinity (floor(inf)=inf
but inf isn't integer-valued), so float?/double? are true for ##Inf and
int?/pos-int?/nat-int?/neg-int? are false for it.
This unblocked many number-test files whose forms previously failed to
READ (##Inf/##NaN literals), so clojure-test-suite jumped from 2241 to 2539
assertions and pass 1719 -> 1955. Baseline raised to 1900. NaN_qmark now runs.
float?/double? on integer-valued doubles (1.0) remain false: Janet represents
an integer and an integer-valued double identically, so they're inherently
indistinguishable — documented in the README Numbers section.
spec: numbers/floats-&-symbolic-values (15 cases). jpm test green.
Closes jolt-fy8 (fixable parts; int-vs-float ambiguity is a documented divergence).
03652dce5d