Resolves issue 0090. The `{}` integer formatter mis-rendered both ends of
the 64-bit range:
- `int_to_string` computed the magnitude as `0 - n`, which overflows for
`s64::MIN` (its magnitude is unrepresentable as a positive s64) — the
value stayed negative, the digit loop ran zero times, so only `-`
printed. It now extracts digits straight from `n` (per-digit
`|n % 10|`, `n` truncating toward zero), never negating MIN.
- `any_to_string`'s `case int:` formatted every integer as s64, so a u64
all-ones value printed as `-1`. There was no `uint` type-category to
distinguish signedness. Added an additive `type_is_unsigned(T)`
reflection builtin (static fold + dynamic interp/LLVM paths, mirroring
`type_name`), backed by the new `TypeTable.isUnsignedInt` predicate, and
a `uint_to_string` formatter (unsigned decimal via long-division over
four 16-bit limbs). `case int:` routes through `type_is_unsigned(type)`.
The 16-bit-limb split is factored into a shared `decompose_u16x4`, now
reused by `int_to_hex_string` (no second unsigned-math routine).
Regression: examples/0046-basic-int-formatter-extremes pins both extremes
plus a width spread; unit tests cover `isUnsignedInt`. Docs (specs.md
representation note, readme std API) updated for unsigned/extreme `{}`
behavior. IR snapshots refreshed for the two new std functions.
Codex review of d6078c2 flagged a blank line at EOF in the new
examples/expected/1202-ffi-cc-c-large-aggregate.ir. Collapse the trailing
newlines to a single one so `git diff --check` is clean. Test-safe: the runner
reads both expected and actual IR through $(...) command substitution, which
strips trailing newlines, so the comparison is unaffected (1202 still ok).
Gate: zig build, zig build test, bash tests/run_examples.sh -> 361/0.
Test-first scaffolding for LLVM backend modularization (Phase A7.1) before the
type/ABI helpers move into src/backend/llvm/{types,abi}.zig. Visibility-only
change to the targets — no behavior change. Closes the ARCH-SAFETY "no generic
ABI snapshot" gap.
- 2 new emit_llvm.test.zig tests:
- abiCoerceParamType across every C-ABI size bucket: <=8 -> i64, 9-16 ->
[2 x i64], >16 -> ptr, HFA (all-float/all-double, <=4 fields) -> unchanged,
string -> ptr, slice -> ptr, scalar -> unchanged. Built via a local
internStruct helper (field slice in the module arena -> no testing-allocator
leak); asserts against emitter.cached_* + LLVMArrayType2.
- needsByval: true only for >16-byte non-HFA struct; false for <=16 / HFA /
string / slice / non-struct.
- 1 new .ir snapshot: 1202-ffi-cc-c-large-aggregate (the canonical callconv(.c)
>16-byte byval example that directly documents abiCoerceParamType) — pins the
byval param path end-to-end (5 byval + entry reload + 2 sret from Arena.init).
Path-free + idempotent (verified across two captures). Suite count unchanged
(snapshot added to an existing example).
- Widened abiCoerceParamType + needsByval to pub (visibility only;
abiCoerceParamTypeEx/materializeByvalArg/verifySizes stay private — move with
callers in sub-step 2). No logic touched.
- Recorded the A7.1 coverage inventory + residual gaps (wasm32 usize->i32 branch,
fn-ptr large-aggregate 1203/1204) in ARCH-SAFETY.md.
Gate: zig build, zig build test, bash tests/run_examples.sh -> 361/0 (no churn
beyond the new 1202 .ir).
