[clang] [clang][test] Rewrote test to work with lit internal shell syntax (PR #105902)

[Paul T Robinson via cfe-commits]

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+import argparse
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pogo59 wrote:

There is a lit substitution `%python` and I see a fair number of these in the lit tests. Some use inline python scripts, some have separate scripts, and a number of them have the python script directly in the test file (`RUN: %python %s ...`). It's far more common in llvm than clang, so you may have better luck looking there for inspiration.

Test files generally do not have license headers.

https://github.com/llvm/llvm-project/pull/105902