[llvm] [lit] Fix shell commands with newlines (PR #67898)

[Thomas Preud'homme via llvm-commits]

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@@ -0,0 +1,2 @@
+# RUN: %{cmds-with-newlines}
+# CHECK: bac
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RoboTux wrote:

Why bac and not abc? Are you trying to make the test fail?

https://github.com/llvm/llvm-project/pull/67898