fix(frontend): ignore unreachable breaks in raw loop validation

[AztecBot]

Summary

Raw loop validation now ignores break statements that are inside compile-time-dead literal if branches. This keeps the frontend's infinite-loop rejection aligned with the SSA lowering path that removes those dead branches before loop codegen.

Fix

• Preserve loop-break accounting only for the reachable branch of literal if true / if false conditions.
• Add regressions for if false { break; } and if true { continue; } else { break; } inside raw loops.

Testing

• cargo test -p noirc_frontend loop_with_break -- --nocapture
• cargo test -p noirc_frontend errors_if_loop_body_type_is_not_unit -- --nocapture
• cargo fmt

Issues

• Closes noir-lang/noir-claude#1041 — raw loop accepted statically unreachable breaks and could compile to an endless Brillig function

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Created by claudebox · group: noir-audit-remediation