Three more value-observable behavior families ported from the C corpus
to in-language @test, routed by the ratified observability rule (value
-> test/lang @test; process-outcome stays in runww). Additive: the .c
sources keep running in $(TESTS), so no byte-id coverage is removed --
de-dup is deferred to fold 6 (task #12).
906_callret_unsigned_arith -> callret_unsigned_test: call-result
unsigned opcode select keyed by callee return type (#168, the N_CALL
twin of gunsigned's module-global #134); operands flow through real
calls so the return-type arm is exercised, not N_IDENT.
912_sar_shr -> sar_shr_test: signed >> / >>= must emit SAR not SHR
(#136); asserts the i64/i32 value directly, dropping the C 8-bit
exit-code encoding.
793_widen_pad_zero -> widen_pad_test: widening a narrow value into a
wider tagged slot zeroes the high pad words (#227).
Batch 2 of the test-arch reframe. These three are codegen-SHAPE tests,
not data-row tests: each subject is a distinct node shape (N_IDENT
module-global read; chained N_INDEX m[i][k]; index-base node-kind). A
[N]struct row-table would interpose its own N_INDEX/N_DOT lowering and
mask the shape under test, so each uses per-shape @test fns with direct
asserts (rob-ratified rule: table where the row is data, per-fn where
the row is a codegen shape). Lossless from the matching
989_{gunsigned,chainidx,idxarg}_run.c; additive (C kept); both stages green.
Proof-of-path for the test-arch reframe: pure-behavior rows become
in-language @test row-tables run by `ww test`, reserving C drivers for
the two irreducible jobs (byte-id + bootstrap). 110_uniesc's 6 value
rows become [N]struct row-tables in a new test/lang/ tree; the trailing
.wwi round-trip stays in C as external-observer residue. Additive — the
C rows are kept; de-dup and make-rewiring land at fold 6 (task #12).
Green on both stages.
