emit-bitexact red on every PR since #7436: its three switch refuse fixtures are not in specs_generate_baseline.txt #7914

emit-bitexact (tools/check_specs_generate.py) is red on every PR that merged master after 21fd562 (#7436). For example, #7626 at e98d6d6:

FAIL: 3 spec(s) newly do not generate with any backend
  bootstrap/tests/fixtures/core_selfhost/refuse/e2_switch_bool_label.t27
  bootstrap/tests/fixtures/core_selfhost/refuse/e2_switch_multi_label.t27
  bootstrap/tests/fixtures/core_selfhost/refuse/e2_switch_statement.t27

These are #7436's both-refuse fixtures. bootstrap/tests/core_selfhost.rs reads them, and gen-c must keep refusing them. #7306 and #7377 recorded their own refuse fixtures in tools/specs_generate_baseline.txt under a "Not a debt" line, and #7436 did not. The job does not run on master pushes, so master shows no red.

Fix: record the three under the same kind of line.

Generated by Claude Code

User Scenarios

• Given the three refuse fixtures from t27core: for over one range and switch as a value, byte-identical to gen-c (Closes #7429) #7436 exist in bootstrap/tests/fixtures/core_selfhost/refuse/, When tools/check_specs_generate.py runs emit-bitexact, Then the fixtures are recognized as expected refusals and the check exits 0.
• Given tools/specs_generate_baseline.txt lacks entries for the three t27core: for over one range and switch as a value, byte-identical to gen-c (Closes #7429) #7436 refuse fixtures, When the baseline is updated with those entries under a "Not a debt" line, Then subsequent emit-bitexact runs on PRs pass without listing those fixtures as newly failing.

Requirements

• FR-001: The three fixture paths MUST be added to tools/specs_generate_baseline.txt under a "Not a debt" comment line.
• FR-002: The entries MUST follow the same format used by self-host P1 slice 1: compound assignment #7306 and self-host P1: pin pub declarations in the t27core fixtures #7377 for their refuse fixtures.
• FR-003: tools/check_specs_generate.py MUST continue to run emit-bitexact and validate against the updated baseline.

Success Criteria

• tools/check_specs_generate.py run on a PR branch containing the baseline update exits 0 and no longer lists the three fixtures as "newly do not generate with any backend".
• The file tools/specs_generate_baseline.txt contains three new lines referencing:
  • bootstrap/tests/fixtures/core_selfhost/refuse/e2_switch_bool_label.t27
  • bootstrap/tests/fixtures/core_selfhost/refuse/e2_switch_multi_label.t27
  • bootstrap/tests/fixtures/core_selfhost/refuse/e2_switch_statement.t27

Boundary

• tools/specs_generate_baseline.txt
• bootstrap/tests/fixtures/core_selfhost/refuse/e2_switch_bool_label.t27
• bootstrap/tests/fixtures/core_selfhost/refuse/e2_switch_multi_label.t27
• bootstrap/tests/fixtures/core_selfhost/refuse/e2_switch_statement.t27
• tools/check_specs_generate.py