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

[Joel E. Denny via llvm-commits]

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

Yes, that was the point.  I've pushed a change to make that clearer.  Thanks.

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