[llvm] [lit] Implement builtin umask (PR #94621)

[LLVM Continuous Integration via llvm-commits]

llvm-ci wrote:

LLVM Buildbot has detected a new failure on builder `mlir-s390x-linux` running on `systemz-1` while building `llvm` at step 6 "test-build-unified-tree-check-mlir".

Full details are available at: https://lab.llvm.org/buildbot/#/builders/117/builds/541

Here is the relevant piece of the build log for the reference:
```
Step 6 (test-build-unified-tree-check-mlir) failure: test (failure)
...
4.757 [1/7/127] Linking CXX executable tools/mlir/unittests/TableGen/MLIRTableGenTests
8.609 [1/6/128] Linking CXX executable tools/mlir/unittests/Target/LLVM/MLIRTargetLLVMTests
14.891 [1/5/129] Linking CXX executable bin/mlir-capi-translation-test
16.128 [1/4/130] Linking CXX executable tools/mlir/unittests/ExecutionEngine/MLIRExecutionEngineTests
16.305 [1/3/131] Linking CXX executable bin/mlir-capi-ir-test
16.368 [1/2/132] Linking CXX executable bin/mlir-capi-pass-test
17.440 [1/1/133] Linking CXX executable bin/mlir-capi-execution-engine-test
17.440 [0/1/133] Running the MLIR regression tests
-- Testing: 2476 tests, 4 workers --
UNRESOLVED: MLIR :: Analysis/DataFlow/test-dead-code-analysis.mlir (1 of 2476)
******************** TEST 'MLIR :: Analysis/DataFlow/test-dead-code-analysis.mlir' FAILED ********************
Exception during script execution:
Traceback (most recent call last):
  File "/home/uweigand/sandbox/buildbot/mlir-s390x-linux/llvm-project/llvm/utils/lit/lit/worker.py", line 76, in _execute_test_handle_errors
    result = test.config.test_format.execute(test, lit_config)
  File "/home/uweigand/sandbox/buildbot/mlir-s390x-linux/llvm-project/llvm/utils/lit/lit/formats/shtest.py", line 29, in execute
    return lit.TestRunner.executeShTest(
  File "/home/uweigand/sandbox/buildbot/mlir-s390x-linux/llvm-project/llvm/utils/lit/lit/TestRunner.py", line 2295, in executeShTest
    return _runShTest(test, litConfig, useExternalSh, script, tmpBase)
  File "/home/uweigand/sandbox/buildbot/mlir-s390x-linux/llvm-project/llvm/utils/lit/lit/TestRunner.py", line 2239, in _runShTest
    res = runOnce(execdir)
  File "/home/uweigand/sandbox/buildbot/mlir-s390x-linux/llvm-project/llvm/utils/lit/lit/TestRunner.py", line 2215, in runOnce
    res = executeScriptInternal(
  File "/home/uweigand/sandbox/buildbot/mlir-s390x-linux/llvm-project/llvm/utils/lit/lit/TestRunner.py", line 1091, in executeScriptInternal
    exitCode, timeoutInfo = executeShCmd(
  File "/home/uweigand/sandbox/buildbot/mlir-s390x-linux/llvm-project/llvm/utils/lit/lit/TestRunner.py", line 205, in executeShCmd
    finalExitCode = _executeShCmd(cmd, shenv, results, timeoutHelper)
  File "/home/uweigand/sandbox/buildbot/mlir-s390x-linux/llvm-project/llvm/utils/lit/lit/TestRunner.py", line 712, in _executeShCmd
    res = _executeShCmd(cmd.rhs, shenv, results, timeoutHelper)
  File "/home/uweigand/sandbox/buildbot/mlir-s390x-linux/llvm-project/llvm/utils/lit/lit/TestRunner.py", line 892, in _executeShCmd
    subprocess.Popen(
TypeError: __init__() got an unexpected keyword argument 'umask'


********************
UNRESOLVED: MLIR :: Analysis/DataFlow/test-liveness-analysis.mlir (2 of 2476)
******************** TEST 'MLIR :: Analysis/DataFlow/test-liveness-analysis.mlir' FAILED ********************
Exception during script execution:
Traceback (most recent call last):
  File "/home/uweigand/sandbox/buildbot/mlir-s390x-linux/llvm-project/llvm/utils/lit/lit/worker.py", line 76, in _execute_test_handle_errors
    result = test.config.test_format.execute(test, lit_config)
  File "/home/uweigand/sandbox/buildbot/mlir-s390x-linux/llvm-project/llvm/utils/lit/lit/formats/shtest.py", line 29, in execute
    return lit.TestRunner.executeShTest(
  File "/home/uweigand/sandbox/buildbot/mlir-s390x-linux/llvm-project/llvm/utils/lit/lit/TestRunner.py", line 2295, in executeShTest
    return _runShTest(test, litConfig, useExternalSh, script, tmpBase)
  File "/home/uweigand/sandbox/buildbot/mlir-s390x-linux/llvm-project/llvm/utils/lit/lit/TestRunner.py", line 2239, in _runShTest
    res = runOnce(execdir)
  File "/home/uweigand/sandbox/buildbot/mlir-s390x-linux/llvm-project/llvm/utils/lit/lit/TestRunner.py", line 2215, in runOnce
    res = executeScriptInternal(

```

https://github.com/llvm/llvm-project/pull/94621