gen-zig: a one-element array constant ([1]u32 = [48]) makes test-report BLOCK trinity specs/reproduce/contracts.t27 #6084

Refs #6081

t27c test-report cannot run the test blocks of gHashTag/trinity specs/reproduce/contracts.t27 (on trinity main, 2026-10-04): the generated Zig fails to compile at spec.zig:29:46, so every test in that spec is reported BLOCKED rather than run. Found while landing gHashTag/trinity#1333. The exact Zig message was not kept; the suspected construct is a one-element array constant and an index into it:

pub const PARSE_DISCARDS : [1]str = ["specs/queen/lotus.t27"];
pub const PARSE_DISCARD_TOKENS : [1]u32 = [48];
...
test the_ledgers_hold_together {
    assert PARSE_DISCARD_TOKENS[0] == 48;
}

Reproduce first. In your container, write the minimal module below to a temp file and run t27c test-report on it, then on trinity's specs/reproduce/contracts.t27. Record the exact Zig error in a comment here. If the cause is not the one-element array, retitle this issue to the real cause before changing anything.

module repro_one_element_array;

pub const PARSE_DISCARDS : [1]str = ["specs/queen/lotus.t27"];
pub const PARSE_DISCARD_TOKENS : [1]u32 = [48];

test one_element_array_indexes {
    assert PARSE_DISCARD_TOKENS[0] == 48;
}

Boundary

• bootstrap/src/compiler.rs
• bootstrap/stage0/FROZEN_HASH
• bootstrap/tests/gen_zig_one_element_array.rs (new)
• docs/now/2026-10-04-gen-zig-one-element-array.md (new; use the date you land it)

bootstrap/src/compiler.rs is held by other cards often; if this card sits in "blocked", that is why, and it waits its turn.

User Scenarios

1. t27c test-report on the minimal module above reports one_element_array_indexes as PASS, not BLOCKED.
2. t27c test-report on trinity specs/reproduce/contracts.t27 runs its tests instead of blocking the whole spec.

Requirements

• FR-001 -- Zig emitted for a [1]T array constant, and for an index into it, compiles (fix the emitter in bootstrap/src/compiler.rs; regenerate nothing under gen/ by hand).
• FR-002 -- bootstrap/tests/gen_zig_one_element_array.rs drives t27c test-report on the minimal module and asserts it is not BLOCKED; a second case uses a [1]str constant.
• FR-003 -- update bootstrap/stage0/FROZEN_HASH for the new compiler.rs the way the repository does it; a docs/now/ entry that names the measured Zig error. CI runs the cargo tests; do not build on the owner's machine.

Success Criteria

• grep -c "fn " bootstrap/tests/gen_zig_one_element_array.rs prints at least 2
• grep -c "test-report" bootstrap/tests/gen_zig_one_element_array.rs prints at least 1