[Mlir-commits] [mlir] [MLIR][DataFlow] Fix two crashes in DeadCodeAnalysis on empty/no-terminator regions (PR #188548)

[LLVM Continuous Integration]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `ppc64le-mlir-rhel-clang` running on `ppc64le-mlir-rhel-test` while building `mlir` at step 6 "test-build-check-mlir-build-only-check-mlir".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/129/builds/41367

<details>
<summary>Here is the relevant piece of the build log for the reference</summary>

```
Step 6 (test-build-check-mlir-build-only-check-mlir) failure: 1200 seconds without output running [b'ninja', b'check-mlir'], attempting to kill
...
PASS: MLIR :: mlir-tblgen/type-constraints.td (3978 of 3988)
PASS: MLIR-Unit :: Interfaces/./MLIRInterfacesTests/11/25 (3979 of 3988)
PASS: MLIR-Unit :: IR/./MLIRIRTests/0/142 (3980 of 3988)
PASS: MLIR-Unit :: IR/./MLIRIRTests/37/142 (3981 of 3988)
PASS: MLIR-Unit :: Interfaces/./MLIRInterfacesTests/12/25 (3982 of 3988)
PASS: MLIR-Unit :: Interfaces/./MLIRInterfacesTests/13/25 (3983 of 3988)
PASS: MLIR-Unit :: IR/./MLIRIRTests/38/142 (3984 of 3988)
PASS: MLIR :: mlir-reduce/dce-test.mlir (3985 of 3988)
PASS: MLIR :: mlir-runner/simple.mlir (3986 of 3988)
PASS: MLIR :: mlir-tblgen/llvm-intrinsics.td (3987 of 3988)
command timed out: 1200 seconds without output running [b'ninja', b'check-mlir'], attempting to kill
process killed by signal 9
program finished with exit code -1
elapsedTime=2554.193480

```

</details>

https://github.com/llvm/llvm-project/pull/188548