[clang] [clang-tools-extra] [clangd][clang-tidy] Factor out mergeFixits() logic and reuse it in clangd (PR #208682)

[Baranov Victor via cfe-commits]

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@@ -166,6 +166,7 @@ clang_target_link_libraries(clangDaemon
   clangBasic
   clangDependencyScanning
   clangDriver
+  clangEdit
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vbvictor wrote:

Can you measure if this increase binary size in any way?

https://github.com/llvm/llvm-project/pull/208682