coredump: test Tarantool LuaJIT unwinding on amd64 and arm64

[dalehamel]

Tarantool LuaJIT coredump coverage

Stacked on the Tarantool runtime port in parca-dev/opentelemetry-ebpf-profiler#316. This PR targets the parent branch in the Shopify fork because GitHub cannot use a fork-only PR head as the base of another PR in parca-dev; it can move upstream once open-telemetry#316 lands or its head is mirrored there.

What this proves

• Adds deterministic amd64 and arm64 coredumps of statically linked, GC64 Tarantool.
• Exercises host-executable detection, hidden-symbol offset extraction, Lua frame recovery, and native handback across Tarantool fibers.
• Resolves real Lua source frames (fib, churn, hot_loop, and main) and native Tarantool frames.
• Documents the expected replay-only ?+0x0 boundary frame and arm64 fiber-trampoline CFI boundary.

The captures use jit.off(true, true). Offline coredump replay is single-pass and cannot perform the live report_pid -> SynchronizeMappings rerun required to associate anonymous JIT mcode with G; interpreter-mode captures therefore provide deterministic end-to-end coverage. JIT mcode remains covered by live profiling and focused extractor tests.

Validation

Both unskipped fixtures pass their exact goldens in architecture-matched Linux development containers:

PASS: TestCoreDumps/testdata/amd64/luajit-tarantool-amd64.json
PASS: TestCoreDumps/testdata/arm64/luajit-tarantool-arm64.json

The amd64 fixture unwinds 22 recursive Lua frames through hot_loop and seven native Tarantool frames. The arm64 fixture recovers churn -> hot_loop -> main before the documented native fiber CFI boundary.

External artifacts

The packed cores/modules are intentionally outside Git. Twelve content-addressed objects (about 99 MiB total) are staged locally but still need uploading to the public parca-coredump-artifacts GCS fallback. dale.hamel@shopify.com can read the bucket but lacks storage.objects.create; a Parca maintainer needs to grant temporary object-creator access or perform the upload before fork CI can fetch them.

[dalehamel]

Superseded by the draft upstream PR parca-dev#317, stacked on parca-dev#316.