[llvm] [llvm-strings] Add --encoding={s,S,utf8} option (PR #221794)

[Harald van Dijk via llvm-commits]

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@@ -0,0 +1,28 @@
+## Show that llvm-strings uses the specified encoding.
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hvdijk wrote:

Okay, fair point that the existing tests are already inconsistent. Based on that, I don't mind `encoding.test` also being inconsistent and have updated it to use the style you said.

https://github.com/llvm/llvm-project/pull/221794