[clang] Use cmake to find perl executable (PR #91275)

[Artem Dergachev via cfe-commits]

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@@ -1,4 +1,4 @@
-REQUIRES: shell
+REQUIRES: perl
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haoNoQ wrote:

A few of those require `rm` and `ls` but these don't count as shell right?

https://github.com/llvm/llvm-project/pull/91275