[llvm] [llvm] Add support for running tests as root (PR #75285)

[Fangrui Song via llvm-commits]

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@@ -13,6 +14,18 @@
 lit_path_displayed = False
 
 
+def user_is_root():
+    # getpass.getuser() can throw an exception in some cases:
+    # See https://github.com/python/cpython/issues/76912
+    try:
+        if getpass.getuser() == "root":
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MaskRay wrote:

*NIX systems can use `os.getuid == 0`

https://github.com/llvm/llvm-project/pull/75285