[llvm] [llvm-lit] Add precommit test to verify current behavior of glob expansion in lit's internal shell (PR #106325)

[Alexander Richardson via llvm-commits]

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@@ -0,0 +1,2 @@
+## This is the first example file used for testing glob pattern matching.
+RUN: This is the first example file.
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arichardson wrote:

```suggestion
```
This file should not contain any RUN: lines especially not ones that cannot actually be run. If you rename it to something like `example_file1.input` lit will not try to run it (since we have `config.suffixes = [".txt"]`).

https://github.com/llvm/llvm-project/pull/106325