[llvm] [llvm-lit][test][NFC] Moved cat command tests into separate lit test file (PR #102366)

[via llvm-commits]

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@@ -0,0 +1,83 @@
+# Check cat command with single file.
+#
+# RUN: rm -rf %T/testCat
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connieyzhu wrote:

I can make these changes in my follow-up patch. For changing %T to %t, how would I get the filepath of %t? I tried looking through the lit documentation and existing tests and I couldn't find a clear answer. Is it something like %t/dir?

https://github.com/llvm/llvm-project/pull/102366