A struct literal initialising an array-typed field as a local
(`e{ encmap = [..] }`) silently dropped the initializer: cg_structlit_fill
(cstage) / cgstructlitfill (wwstage) had no TY_ARRAY field arm, so the
array field fell to the generic scalar tail — cgexpr the N_ARRLIT (→ AX≈0)
then store one sized word — losing every element. cstage returned 0;
wwstage emitted byte-identical wrong code. (The GLOBAL literal-init path
is unaffected: it goes through emit_struct_lit_bytes, already correct via
#129 A.3.)
Both stages now element-wise store the N_ARRLIT at base+field_off+i*esz,
reusing the proven N_LET array-init shape (cgen.c:8467 / cgenstmt.ww:1393)
for int and float elements plus its `...` repeat fill; esz routes through
the type table (rule 13). str/slice/struct/tagged ELEMENT arrays are the
N_LET path's documented multi-word gap (cgen.c:8462) — converted from the
silent drop to a LOUD rule-7 error in both stages, not left silent.
Symmetric both stages (rule 10), byte-identical .s.
The `...` repeat in a struct-literal array field is checker-unreachable
today (the field type-check rejects `[v...]` length inference — a
separate checker gap); the arm mirrors N_LET's repeat for symmetry.
Test 949_structlit_arrfield_run: +local literal-init reads (idx 0 / last
element), cstage run + cs==ww byte-id.
Reading an array-typed field of a module-global struct value (`G.arr[i]`)
silently miscompiled: the N_INDEX fallback's cg_dotbase_addr (cstage) /
dotbaseaddr (wwstage) helper — the #135 sibling that computes &(s.field)
for a `[N]T` field — had no module-global-struct base arm. cstage emitted
`LEAQ (BP)` (localfind returns 0 for a global, so it read the stack frame
→ 0); wwstage's localfindnode returned nil and the fallback keyed on the
FIELD name, so it returned false and the caller's cgexpr(N_DOT) loaded the
field VALUE as a pointer → SEGFAULT. The .data was already correct
(emit_struct_lit_bytes #129 A.3); only the READ base address was wrong.
Both stages now emit `LEAQ name(SB) (+ ADDQ field_off)` for a global
value-struct base, mirroring the scalar global-field read (cgen.c:7532);
const globals resolve via def_isstructdef. Symmetric both stages (rule
10), byte-identical .s. Unblocks base64's `const std_encoding.encmap[i]`
reads (#22).
Test 949_structlit_arrfield_run: global `let`/`def` struct array-field
read, cstage run + cs==ww byte-id.
