[llvm] Create a CharSetConverter class with both iconv and icu support (PR #74516)

[Eli Friedman via llvm-commits]

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@@ -295,6 +296,14 @@ add_llvm_component_library(LLVMSupport
   Demangle
   )
 
+# Link icu library if it is an external library.
+if(ICU_FOUND)
+  target_link_libraries(LLVMSupport
+  PRIVATE
+  ${ICU_LIBRARIES}
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efriedma-quic wrote:

My understanding of https://discourse.llvm.org/t/rfc-enabling-fexec-charset-support-to-llvm-and-clang-reposting/71512/30 was that the point of only allowing dynamically linked ICU was to avoid the attribution requirement?  Or am I misunderstanding something here?

https://github.com/llvm/llvm-project/pull/74516