Two failing E2E tests pinning the two legs of the #51 codegen crash,
both rooted in the `Term::New` desugar dropping `NewArg::Type`
(crates/ailang-core/src/desugar.rs:1053):
- Leg 1 (legitimate): `(new RawBuf (con Int) 3)` used only via
`RawBuf.size` — never observed by get/set, so the dropped `(con Int)`
is the sole element-type carrier. The unpinned forall var defaults to
Unit in mono and `ail build --alloc=rc` aborts on the unregistered
`RawBuf_new__Unit` intercept. Pins build+run printing `3`.
- Leg 2 (forbidden): `(new RawBuf (con Unit) 3)` — Unit is outside the
param-in set {Int, Float, Bool}, but the dropped type-arg never reaches
param-in enforcement, so `ail check` wrongly passes. Pins a
`param-not-in-restricted-set` rejection naming Unit at check time.
Both RED at HEAD. GREEN side carries the explicit element type from
Term::New through to monomorphisation (must not mint __Unit) and adds the
leg-2 reject pre-desugar per the Term::New/desugar lockstep.
refs #51
Brummel
61b9d3f513