[clang-tools-extra] [llvm] [clang-doc] Adds a mustache backend (PR #133161)

[Paul Kirth via llvm-commits]

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@@ -0,0 +1,104 @@
+//===- mustache.cpp - The LLVM Modular Optimizer
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ilovepi wrote:

Can you remove this since you have a separate PR for it?

https://github.com/llvm/llvm-project/pull/133161