Hojun-Cho
7db30bf609
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).