[Fix] Break JIT cache-key dependency-traversal recursion cycles

[sjfeng1999]

_collect_dependency_sources used a visited set to guard against cycles, but the JitFunction branch went through
val._ensure_cache_manager() -> _jit_function_cache_key -> _collect_dependency_sources(<fresh visited>), bypassing the caller's visited. During that computation manager_key is still None, so there was no reentrancy guard: any jit self-reference, jit<->jit mutual reference, or a .launch attribute name colliding with a same-named top-level @flyc.jit would recurse until RecursionError.

Add a per-instance _computing_manager_key flag, set while a JitFunction computes its own key. When the dependency traversal meets a JitFunction already computing its key (a cycle), emit a stable jit-recursive:<name>:<label> placeholder instead of reentering. Each cycle member's own source still enters the key via its own _get_func_source, so the placeholder only breaks the cycle.

Acyclic code never hits the placeholder branch, so existing cache keys (and on-disk cache) are unchanged.

Add regression tests for top-level launch attribute collision, jit self-reference, and jit<->jit mutual reference.

Motivation

Technical Details

Test Plan

Test Result

Submission Checklist

• Look over the contributing guidelines at https://github.com/ROCm/ROCm/blob/develop/CONTRIBUTING.md#pull-requests.

[Copilot]

Pull request overview

This PR fixes a recursion bug in JIT cache-key dependency traversal: _collect_dependency_sources() could re-enter cache-key computation via JitFunction._ensure_cache_manager() using a fresh visited set, causing unbounded recursion (e.g., self-reference, mutual jit references, or .launch name collisions with a top-level @flyc.jit named launch).

Changes:

• Add a reentrancy guard (_computing_manager_key) to JitFunction and emit a stable jit-recursive:<name>:<label> placeholder when a cycle is detected during dependency collection.
• Wrap manager-key computation in try/finally to ensure the guard is cleared even on errors.
• Add regression tests covering .launch attribute collision, jit self-reference, and mutual jit references; improve _load_mod() to dedent module bodies for readability.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

File	Description
python/flydsl/compiler/jit_function.py	Adds cycle-breaking logic for dependency-source collection and a per-instance “computing manager key” guard.
tests/unit/test_jit_cache_key_completeness.py	Adds regression tests for recursion-cycle scenarios and updates module loader to dedent test module sources.

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