[llvm] cmake: Derive CMake system name from a triple via new mechanism (PR #208773)

[Petr Hosek via llvm-commits]

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@@ -0,0 +1,6 @@
+# Run the unit tests for get_triple_system_name.py, which parses
+# TripleName.def and must stay in sync with llvm::Triple.
+
+# RUN: "%python" %S/get_triple_system_name_test.py 2>&1 | FileCheck %s
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petrhosek wrote:

I don't think `%python` should be quoted, this results in the string being double quoted which negates the quotes (e.g. `""C:\Program Files\Python310\python.exe""`):
```suggestion
# RUN: %python %S/get_triple_system_name_test.py 2>&1 | FileCheck %s
```

https://github.com/llvm/llvm-project/pull/208773