julia

c0284d59 - codegen: Replace ThreadSafeContext manual locking with withContextDo

codegen: Replace ThreadSafeContext manual locking with withContextDo LLVM 21 removes `ThreadSafeContext::getLock()`, `::Lock`, and `::getContext()`, replacing them with callback-based `ThreadSafeContext::withContextDo(callback)`. Add a `withContextDo` compatibility shim that works on both LLVM 20 (acquires lock + calls callback) and LLVM 21+ (delegates to the new API). Update all callsites to use scoped locking through this shim instead of manual lock/unlock. Key changes: - `jl_codegen_output_t` no longer holds a persistent `tsctx_lock`. All context access goes through `withContextDo`, with debug asserts ensuring `get_context()`/`get_module()` are only called inside the callback scope. - `addOutput()` and `R->replace()` are called outside `withContextDo` to respect the lock hierarchy (TSC locks must be released before dispatching materialization units). - `jl_create_ts_module` and `compileModule` use the free-function shim. - `disasm.cpp` replaces `std::optional<ThreadSafeContext::Lock>` with the callback pattern. Supersedes JuliaLang/julia#59946. Co-Authored-By: yuyichao <yyc1992@gmail.com> Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>