Atomic remove isl issue

```
enzymexlamlir-opt --remove-atomics /root/.bazel/sandbox/processwrapper-sandbox/15617/execroot/__main__/bazel-out/k8-dbg/bin/test/lit_tests/remove_atomic_rmw.mlir.test.runfiles/__main__/test/lit_tests/remove_atomic_rmw.mlir --split-input-file | FileCheck /root/.bazel/sandbox/processwrapper-sandbox/15617/execroot/__main__/bazel-out/k8-dbg/bin/test/lit_tests/remove_atomic_rmw.mlir.test.runfiles/__main__/test/lit_tests/remove_atomic_rmw.mlir # RUN: at line 1
+ enzymexlamlir-opt --remove-atomics /root/.bazel/sandbox/processwrapper-sandbox/15617/execroot/__main__/bazel-out/k8-dbg/bin/test/lit_tests/remove_atomic_rmw.mlir.test.runfiles/__main__/test/lit_tests/remove_atomic_rmw.mlir --split-input-file
+ FileCheck /root/.bazel/sandbox/processwrapper-sandbox/15617/execroot/__main__/bazel-out/k8-dbg/bin/test/lit_tests/remove_atomic_rmw.mlir.test.runfiles/__main__/test/lit_tests/remove_atomic_rmw.mlir
src/external/isl/isl_ctx.c:307: isl_ctx not freed as some objects still reference it
src/external/isl/isl_ctx.c:307: isl_ctx not freed as some objects still reference it
src/external/isl/isl_ctx.c:307: isl_ctx not freed as some objects still reference it
src/external/isl/isl_ctx.c:307: isl_ctx not freed as some objects still reference it
src/external/isl/isl_ctx.c:307: isl_ctx not freed as some objects still reference it
src/external/isl/isl_ctx.c:307: isl_ctx not freed as some objects still reference it
src/external/isl/isl_ctx.c:307: isl_ctx not freed as some objects still reference it
src/external/isl/isl_ctx.c:307: isl_ctx not freed as some objects still reference it
src/external/isl/isl_ctx.c:307: isl_ctx not freed as some objects still reference it
src/external/isl/isl_ctx.c:307: isl_ctx not freed as some objects still reference it
src/external/isl/isl_ctx.c:307: isl_ctx not freed as some objects still reference it
src/external/isl/isl_ctx.c:307: isl_ctx not freed as some objects still reference it
src/external/isl/isl_ctx.c:307: isl_ctx not freed as some objects still reference it
src/external/isl/isl_ctx.c:307: isl_ctx not freed as some objects still reference it
src/external/isl/isl_ctx.c:307: isl_ctx not freed as some objects still reference it
src/external/isl/isl_ctx.c:307: isl_ctx not freed as some objects still reference it
src/external/isl/isl_ctx.c:307: isl_ctx not freed as some objects still reference it
src/external/isl/isl_ctx.c:307: isl_ctx not freed as some objects still reference it
src/external/isl/isl_ctx.c:307: isl_ctx not freed as some objects still reference it
src/external/isl/isl_ctx.c:307: isl_ctx not freed as some objects still reference it
src/external/isl/isl_ctx.c:307: isl_ctx not freed as some objects still reference it
src/external/isl/isl_ctx.c:307: isl_ctx not freed as some objects still reference it
src/external/isl/isl_ctx.c:307: isl_ctx not freed as some objects still reference it
src/external/isl/isl_ctx.c:307: isl_ctx not freed as some objects still reference it
src/external/isl/isl_ctx.c:307: isl_ctx not freed as some objects still reference it
src/external/isl/isl_ctx.c:307: isl_ctx not freed as some objects still reference it
src/external/isl/isl_ctx.c:307: isl_ctx not freed as some objects still reference it
src/external/isl/isl_ctx.c:307: isl_ctx not freed as some objects still reference it
src/external/isl/isl_ctx.c:307: isl_ctx not freed as some objects still reference it
src/external/isl/isl_ctx.c:307: isl_ctx not freed as some objects still reference it
```

from ci @ftynse @ivanradanov

Start by reproducing the command shown for test/lit_tests/remove_atomic_rmw.mlir with --remove-atomics and --split-input-file. Inspect the test and the reported isl_ctx.c:307 warning to determine which context references remain; done means the test completes without repeated isl context cleanup warnings.

Written by the indexing model from the issue text.