Replace STACKLESS_PROPOSE(func) in do_call() and ext_do_call() by
STACKLESS_PROPOSE_ALL().

- Initialize variable 'len' in function unwrap_frame_arg().
- Assign to '*valid' in function slp_find_execname().
- Disable GCC warning -Waddress in macro TASKLET_SETVAL(task, val).
- Update Stackless/changelog.txt for issues python#138, python#140

Replace STACKLESS_PROPOSE(func) in do_call() and ext_do_call() by
STACKLESS_PROPOSE_ALL().
(cherry picked from commit ae3d7a2)

- Assign to '*valid' in function slp_find_execname().
- Disable GCC warning -Waddress in macro TASKLET_SETVAL(task, val).
- Update Stackless/changelog.txt for issues python#138, python#140

(cherry picked from commit 3461ccf)

…ary domains

W-PROTOCOL-CODIFY Phase A per supervisor 20:03:34Z directive (post pythia
python#138 python#3 + supervisor 19:37:39Z STRONG CONCUR + theologian 19:37:17Z spec).

Replaces named-only conversions (post W-2B-RECONVERT 3-class fix at
8e0c73e) with single-field struct typedefs that the C compiler tracks
distinctly. Inline arithmetic at the seam was the bug class, named
conversions were the WEAKER form (HirType negative control: 14
reinterpret_casts shipped broken until 2026-04-15 because naming
degrades to advisory). PhxMem has_base structural flag is the POSITIVE
control: JIT_CHECK_C didn't fire on dual-arch gate; structural prevention
worked.

CHANGES (Python/jit/bytecode_c.h):
- typedef struct { int v; } BcByteOffset;
- typedef struct { int v; } BcInstrIndex;
- phx_bc_offset_to_instr_index now takes BcByteOffset, returns BcInstrIndex
- phx_bc_instr_index_to_offset now takes BcInstrIndex, returns BcByteOffset
- Header comment cites P5 origin + paired empirical controls

CHANGES (Python/jit/hir/builder_emit_c.c, build_inline_except_opcode_array_c):
- Class A site: wrap except_body_offset in BcByteOffset, convert to
  BcInstrIndex, unwrap .v for jit_bc_instr_init (existing raw-int API)
- Class C site: wrap jit_bc_instr_base_offset return in BcInstrIndex,
  convert to BcByteOffset, unwrap .v for entry->base_offset
- Class B site: wrap jit_bc_instr_get_jump_target return in BcInstrIndex,
  convert to BcByteOffset, unwrap .v for phx_block_map_lookup_or_panic

The wrap/unwrap dance localizes the .v access to exactly the boundary
between raw-int existing APIs and typed conversion functions. Compiler
will catch any future cross-domain assignment (e.g., assigning
BcByteOffset to BcInstrIndex without conversion) as type error — the
structural property the spec requires.

Spec: docs/w-protocol-codify-spec.md P5 (lines 109-136).

Behavior: ZERO change. The numeric values are identical to the named-
conversion fix at 8e0c73e (same arithmetic, same call ordering). The
30/30 sentinels (test_exc_raise_catch + 3 W-2B-RECONVERT sentinels) +
test_multiple_exceptions_in_loop must remain 30/30 PASS.

OUT-OF-SCOPE for Phase A (per spec):
- Other domains (cache-id, ref-kind, type-kind) — apply pattern as
  encountered, not pre-authored.
- Existing C++ BCOffset/BCIndex code — already type-enforced in C++.
- jit_bc_instr_* APIs — keep raw int signatures; conversion happens at
  call sites in helpers that cross domains. Future Phase: if a new
  helper repeatedly wraps/unwraps the same value, consider promoting
  the return type to BcInstrIndex / BcByteOffset.

Phase B (gate integration) + Phase C (per-conversion P6/P7 application
to emitAnyCall + emitLoadMethodStatic) queued post-Phase-A.

Verification pending: testkeeper rebuild + 30x W-2B-RECONVERT sentinel
suite + 30x test_multiple_exceptions_in_loop + full Phoenix gate +
ABBA + dual-arch.

Per supervisor 20:39:03Z directive (post pythia python#138 python#2: push 55 was the
first commit in 'ACTIVE-dispatch territory' — Class A unit bug previously
masked dispatch-loop coverage on multi-except paths via interpreter
fallback for the entire push-54 lifetime).

Adds 4 sentinels covering exception-handling shapes not exercised by the
W-2B-RECONVERT sentinels (which targeted Class A/B/C latent fixes):

1. test_exc_try_else — no-raise path + else branch. Exercises the
   no-fire route through emitInlineExceptionMatch fast-path + JIT_EVAL
   falls through to else block.

2. test_exc_try_finally_with_raise — nested try/finally inside try/except
   with raise(). The raise-CALL exercises emitCallExceptionHandler's D1
   stack-cleanup pre-amble + D3 result re-push invariant when an inner
   finally runs while the exception propagates to the outer try.

3. test_exc_nested_try_inner_catches — nested try where inner except
   catches and outer block continues normally. Exercises FrameState
   depth-trim correctness across nested handler scope transitions.

4. test_exc_raise_in_handler — re-raise a DIFFERENT exception type from
   inside an except handler. The new raise() inside except is itself
   a CALL (constructor of the new exception class), so
   emitCallExceptionHandler fires while we're already in handler dispatch
   — tests nested handler activation.

Tests 2-4 actively exercise emitCallExceptionHandler dispatch. Test 1
covers emitInlineExceptionMatch no-fire path. Together they cover the
four major dispatch shapes not exercised by W-2B-RECONVERT sentinels.

Per theologian 20:40:59Z patch-shape APPROVE. Verification pending:
testkeeper 30x each + regression check on existing 5 W-2B-RECONVERT
sentinels (helper unchanged at push 56).

If all 4 PASS → C dispatch path is sound for these shapes; W-2A-DISPATCH-
COVERAGE complete; pivot to W-PROTOCOL-CODIFY Phase B per roadmap.
If any FAIL → new bug discovery; investigate per HIR-diff Phase 0
methodology (compare to push-53 ebec018 reference for the failing
shape per theologian 20:40:59Z).