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

[Paul T Robinson via llvm-commits]

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@@ -565,6 +566,18 @@ class SHFILEOPSTRUCTW(Structure):
     return ShellCommandResult(cmd, "", stderr.getvalue(), exitCode, False)
 
 
+def executeBuiltinUmask(cmd, shenv):
+    """executeBuiltinUmask - Change the current umask."""
+    if len(cmd.args) != 2:
+        raise InternalShellError(cmd, "'umask' supports only one argument")
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pogo59 wrote:

```suggestion
        raise InternalShellError(cmd, "'umask' requires exactly one argument")
```

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