Surface rename of the signed integer family: s1..s64 become i1..i64
(u1..u64, usize, isize unchanged). 'string' keeps the s-prefix arm in
name classification; width parsing moves to the i-prefix arm next to
isize.
Internal TypeId tags follow the surface (.s8/.s16/.s32/.s64 ->
.i8/.i16/.i32/.i64), as do mono-key mangle fragments (ptr_i64,
tu_i64_bool) and all display/diagnostic formatting (i{d}).
Migrated in the same sweep: stdlib + examples + issue repros + FFI C
companions (shared symbol names like ffi_id_i64), expected
stdout/stderr/ir snapshots, specs.md, readme.md, CLAUDE.md/AGENTS.md,
implementation_plan.md, docs/, issue writeups. Vendored stb_image and
historical flow state left untouched.
zig build test: 426/426; examples suite: 595/595.
An array const's '.len' and 'K[<const idx>]' element reads, and a
struct const's field ('LIT.r'), fold as compile-time integer leaves —
usable in array dimensions and other constants' initializers. All
source-aware (the SELECTED author's elements, folded in the author's
context with the cyclic-definition frame); a const out-of-range index
diagnoses at fold time, never wraps.
- evalConstIntExpr gains the three ctx hooks (lookupConstAggLen /
lookupConstArrayElem / lookupConstStructField) + an index_expr arm;
all five ctx implementations extended (stateless tiers fold null).
- Array consts dual-register in module_const_map (value = the literal
node) so the folders see elements; bare reads still hit the GLOBAL
arm first, so no double emission.
- Untyped consts whose RHS is a const-aggregate leaf ('L :: K.len',
'E :: K[1]', 'R :: LIT.r') register in a pass 2b AFTER aggregates,
gated on the receiver naming a const aggregate — a namespaced member
('F :: m.PI_ISH') is never mis-typed by the count placeholder.
Examples: 0179 (folds in dims + const exprs), 1163 (OOB diagnostic).
