feat(igla): Wave Loop 892 — module-scope [603][2]^6 Pt non-power-of-two outer-dimension array-of-struct variable from call with indexed signed writes #1845

Next mechanical step in the packed-vector array-of-struct ladder.

• Outer dimension: 603 (non-power-of-two)
• Inner struct: [2]^6 Pt (384 bits per element)
• Total elements: 603 × 64 = 38,592
• Packed vector width: 38,592 × 32 = 1,234,944 bits (~1.178 MiBit)

Pattern: module-scope variable initialized from a pure function call, mutated via signed-index field writes, read back with assert_eq inside a bench block.

Expected zero compiler / FROZEN_HASH changes.

🤖 Generated with Claude Code

User Scenarios

• Given a module-scope variable of outer dimension 603 (non-power-of-two) containing an array-of-struct with inner dimension [2]^6 Pt (384 bits per element), When the variable is initialized from a pure function call and mutated via signed-index field writes, Then reading back the values with assert_eq inside a bench block must produce the expected results.

Requirements

• FR-001: The compiler MUST accept module-scope array-of-struct variables with non-power-of-two outer dimensions.
• FR-002: The compiler MUST correctly initialize module-scope variables from pure function calls.
• FR-003: The compiler MUST support signed-index field writes to mutate array-of-struct elements.
• FR-004: The bench block assert_eq MUST verify the mutated values match expectations.

Success Criteria

• t27c specs/tools/tri/loop.t27 compiles successfully and exits 0
• t27c specs/tri/collections/array.t27 compiles successfully and exits 0
• t27c specs/memory/graph/scope.t27 compiles successfully and exits 0

Boundary

• specs/tools/tri/loop.t27
• specs/tri/collections/array.t27
• specs/memory/graph/scope.t27