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.
lazyLowerFunction's three exit paths (non-null branch, already-promoted
early return, null-FuncId `ns.fn` qualified-alias branch) each duplicated
the caller-state restore, and the null branch's copy had drifted: it
restored every saved field EXCEPT `block_terminated`. A qualified alias
whose body terminates (e.g. a constant-folded `if true { return ... }`)
leaves `block_terminated = true` after lowerFunction; the null path
returned without resetting it, so the flag leaked into the CALLER's body
lowering and the caller's own trailing statements / `return` were rejected
as dead-after-terminator ("function ... body produces no value").
Fix: collapse the three restores into a single `defer` registered right
after the state is saved, so every exit path restores the identical full
set and the class cannot diverge again. Fields restored on all paths:
current_source_file (F1), scope, func_defer_base, block_terminated (F2),
force_block_value, builder.func/current_block/inst_counter. The
foreign-class / jni-env / pack-mono / inline-return fields already had
their own defers and are unchanged.
Regression: examples/0721-modules-qualified-terminating-callee.sx — a
qualified alias `m.foo` folds `if true { return helper(); }` (helper from
m.sx's own import) and is followed by caller statements + the caller's own
`return 0`. Reports "body produces no value" pre-fix; prints
"terminating-callee: ok" / "after" and exits 0 after. 0719 (collision) and
0720 (F1 own-import visibility) stay green. issues/0100 RESOLVED banner
extended with the F2 follow-up.
